8. Basic Object-Oriented Python (127m) Flashcards
What is Object Oriented Programming in Python? What is Properties and Behaviours?
Object-oriented programming (OOP) is a programming paradigm that organizes code into objects, which are instances of classes. Python is an object-oriented programming language that supports the creation and manipulation of objects.
In OOP, objects are the building blocks that encapsulate data (properties) and behavior (methods or functions) together. Let’s delve deeper into properties and behaviors:
- Properties: Properties represent the data or attributes associated with an object. They define the state of an object and store information. In Python, properties are typically represented by variables or attributes within a class. Each object of a class has its own set of property values.
For example, consider a class named “Car.” The properties of a car object might include its color, brand, and model. These properties can be defined as variables within the class:
```python
class Car:
def __init__(self, color, brand, model):
self.color = color
self.brand = brand
self.model = model
~~~
Here, color, brand, and model are properties of the car object. You can create instances of the class and assign specific values to these properties:
```python
my_car = Car(“red”, “Toyota”, “Camry”)
print(my_car.color) # Output: red
~~~
- Behaviors: Behaviors represent the actions or operations that an object can perform. They define how an object can interact with other objects or manipulate its own state. In Python, behaviors are typically implemented as methods or functions within a class.
Continuing with our “Car” example, let’s define a behavior for the car object, such as starting the engine:
```python
class Car:
def __init__(self, color, brand, model):
self.color = color
self.brand = brand
self.model = model
def start_engine(self):
print("Engine started!") ~~~
The start_engine method allows the car object to perform the action of starting the engine. You can call this method on an instance of the class:
```python
my_car = Car(“red”, “Toyota”, “Camry”)
my_car.start_engine() # Output: Engine started!
~~~
In this case, start_engine() is the behavior associated with the car object. Different objects of the same class can invoke their own behaviors while maintaining their individual property values.
Object-oriented programming provides a powerful way to model real-world concepts, allowing you to define and manipulate objects with their own properties and behaviors.
What is OOP?
Vocab:
* OOP = Object-Oriented Programming
* Object-Oriented Programming = a way of structuring your code into groups of properties and behaviors
Example Object: Car
Properties:
* 4 wheels
* 2 doors
* Make
* Model
* Year
Behaviors:
* Stop
* Go
* Turn
Python objects
Here are the Python docs about each of these objects. It’s a good habit to check out the documentation and start getting used to reading about how things work.
* List
* String
* Dictionary
* Tuple
Things I’ve interacted with today:
Dog
* Properties: 2 eyes, 2 ears, tail
* Behaviors: fetch, bark, whine, wag tail
Oven
* Properties: buttons, door, racks, light
* Behaviors: heating, timer, light on/off
What is a class and how to write it in Python?
In Python, a class is a blueprint for creating objects. It serves as a template that defines the properties (attributes) and behaviors (methods) that objects of that class will have. The class specifies the common characteristics and functionalities shared by its instances (objects).
To define a class in Python, you use the class keyword followed by the class name. Here’s a basic syntax for creating a class:
```python
class ClassName:
# class variables and methods go here
~~~
Inside the class, you can define various elements, including:
- Constructor Method: The constructor method
\_\_init\_\_()is called when an object of the class is instantiated. It is used to initialize the object’s properties. It must haveselfas the first parameter, which refers to the object itself.
```python
class ClassName:
def __init__(self, parameter1, parameter2, …):
# initialize properties here
self.property1 = parameter1
self.property2 = parameter2
~~~
- Instance Methods: Instance methods are functions defined within the class that can be invoked on objects of the class. They can access and manipulate the object’s properties using the
selfparameter.
```python
class ClassName:
def __init__(self, parameter1, parameter2, …):
self.property1 = parameter1
self.property2 = parameter2
def method1(self, parameter1, parameter2, ...):
# method code goes here ~~~
- Class Variables: Class variables are shared among all instances of the class. They are defined within the class but outside any method. They can be accessed using the class name or any instance of the class.
```python
class ClassName:
class_variable = value
def \_\_init\_\_(self, parameter1, parameter2, ...):
self.property1 = parameter1
self.property2 = parameter2 ~~~
Here’s an example that puts it all together:
```python
class Car:
wheels = 4 # class variable
def \_\_init\_\_(self, color, brand, model):
self.color = color
self.brand = brand
self.model = model
def start_engine(self):
print("Engine started!")
def drive(self, distance):
print(f"The {self.color} {self.brand} {self.model} is driving {distance} miles.") ~~~
You can create instances of the class using the class name followed by parentheses, passing the required arguments to the constructor:
```python
my_car = Car(“red”, “Toyota”, “Camry”)
~~~
You can then access the object’s properties and invoke its methods:
```python
print(my_car.color) # Output: red
my_car.start_engine() # Output: Engine started!
my_car.drive(100) # Output: The red Toyota Camry is driving 100 miles.
~~~
This is a basic overview of defining a class in Python. Classes provide a way to create reusable and organized code, allowing you to model complex systems and create objects with specific behaviors and attributes.
Explain the following code:
class Car():
pass
my_car = Car()
print(my_car)
print(type(my_car))
print(isinstance(my_car, Car))
What output will it give?
The code snippet you provided creates a class called Car and then creates an instance of that class named my_car. It then prints the object, its type, and checks whether the object is an instance of the Car class using the isinstance() function. Let’s break down the code and examine the output it will produce:
```python
class Car():
pass
~~~
In this line, a class named Car is defined using the class keyword. The pass statement acts as a placeholder, indicating that the class body is empty. This means the Car class doesn’t have any specific properties or methods defined.
```python
my_car = Car()
~~~
Here, an instance of the Car class is created using the class name followed by parentheses. The parentheses () indicate the invocation of the class constructor or initializer method, \_\_init\_\_(). Since the class body is empty, this instance won’t have any specific properties or behaviors.
```python
print(my_car)
~~~
This line prints the value of the my_car object. However, since the Car class doesn’t have any specific implementation or string representation defined, the output will be something like <\_\_main\_\_.Car object at 0x...>. The specific memory address (0x...) may vary.
```python
print(type(my_car))
~~~
This line prints the type of the my_car object using the type() function. It will output <class '\_\_main\_\_.Car'>, indicating that my_car is an object of the Car class defined in the current module (\_\_main\_\_).
```python
print(isinstance(my_car, Car))
~~~
This line checks whether my_car is an instance of the Car class using the isinstance() function. It will return True if my_car is an instance of the Car class, and False otherwise. Since my_car is indeed created using the Car class, the output will be True.
So, overall, the code will produce the following output:
<\_\_main\_\_.Car object at 0x...> <class '\_\_main\_\_.Car'> True
The specific memory address (0x...) and representation may vary, but the output confirms that my_car is an object of the Car class and is indeed an instance of the Car class.
What does print(), type(), isinstance() do in classes and how can it help me identify classes?
In Python, the print(), type(), and isinstance() functions are commonly used tools to work with classes and objects. Here’s an explanation of what each of these functions does and how they can help you identify classes and objects:
-
print(): Theprint()function is used to display output on the console. When applied to an object, it calls the object’s\_\_str\_\_()method to get a string representation of the object, which is then printed. It helps you examine the value or representation of an object, such as its properties or other relevant information. -
type(): Thetype()function is used to determine the type of an object. When passed an object as an argument, it returns the type or class of that object. It helps you identify the class to which an object belongs. -
isinstance(): Theisinstance()function is used to check whether an object is an instance of a particular class. It takes two arguments: the object you want to check and the class you want to compare it against. It returnsTrueif the object is an instance of the class, andFalseotherwise. It helps you verify the relationship between an object and a class.
These functions are often used during development and debugging to inspect objects and verify their types. They can be helpful in the following scenarios:
- Identifying the class of an object: You can use
type()to determine the class of an object. This is particularly useful if you have multiple classes and want to confirm which class an object belongs to. - Verifying inheritance or class relationships:
isinstance()can be used to check if an object is an instance of a specific class or any of its derived classes. This helps in understanding the inheritance hierarchy and confirming relationships between classes. - Debugging and troubleshooting: By printing the object using
print(), you can examine its properties, values, or other relevant information to understand its current state and aid in debugging your code.
Overall, these functions are valuable tools for inspecting and understanding classes and objects during development, allowing you to identify classes, verify relationships, and gain insights into object properties.
When creating a blueprint for an object, you use the ` ______ `keyword. Fill in the blanks.
When creating a blueprint for an object, you use the class keyword.
Explain the following code:
class Car():
wheels = 4
doors = 2
engine = True
car_one = Car()
car_two = Car()
car_two.doors = 6
Car.doors = 4
print(f'Car One: {car_one.doors}')
print(id(car_one.doors))
print(f'Car Two: {car_two.doors}')
print(id(car_two.doors))
print(f'Car Global: {Car.doors}')
print(id(Car.doors))
What output will it give and also explain ID and will ID change if following change is made to the code Car.doors = 5.
The given code defines a Car class with some class-level attributes and creates two instances of the Car class. Here’s a breakdown of the code and its output:
```python
class Car():
wheels = 4
doors = 2
engine = True
~~~
In this section, a Car class is defined with three class-level attributes: wheels, doors, and engine. These attributes define the characteristics of a car and are shared among all instances of the Car class.
```python
car_one = Car()
car_two = Car()
~~~
Two instances of the Car class, car_one and car_two, are created using the class constructor. Both instances will have the same initial attribute values inherited from the class.
```python
car_two.doors = 6
Car.doors = 4
~~~
The attribute doors of car_two is modified directly, changing its value to 6. This modification affects only the doors attribute of car_two and doesn’t change the class-level attribute or affect other instances.
The class-level attribute doors is also modified by directly accessing it via the Car class itself. The value is changed to 4, and this change affects all instances of the Car class.
```python
print(f’Car One: {car_one.doors}’)
print(id(car_one.doors))
print(f’Car Two: {car_two.doors}’)
print(id(car_two.doors))
print(f’Car Global: {Car.doors}’)
print(id(Car.doors))
~~~
The print statements in this section output the values of doors for car_one, car_two, and the class Car itself. The id() function is used to retrieve the unique identifier of the object referenced by the attribute.
Output:
Car One: 2 <id1> Car Two: 6 <id2> Car Global: 4 <id3>
Explanation of the output:
-
Car One: 2: The value ofdoorsforcar_oneis 2, which is the initial value inherited from the class. This value hasn’t been modified forcar_one. -
<id1>: The unique identifier (memory address) of the object referenced bycar_one.doors. -
Car Two: 6: The value ofdoorsforcar_twois 6, which was directly modified for this instance. -
<id2>: The unique identifier (memory address) of the object referenced bycar_two.doors. -
Car Global: 4: The value of the class-level attributedoorsafter it was modified usingCar.doors = 4. -
<id3>: The unique identifier (memory address) of the object referenced byCar.doors.
Regarding the question about the id changing if Car.doors = 5 is made:
If you change Car.doors = 5 before the print statements, the output will be:
Car One: 2 <id1> Car Two: 6 <id2> Car Global: 5 <id4>
The id of car_one.doors and car_two.doors will remain the same since their values haven’t changed. However, the id of Car.doors will change because the value of the class-level attribute has changed, resulting in a new object being created with the value 5.
What is instance attribute in Python?
In Python, an instance attribute is a variable that belongs to a specific instance of a class. It is defined within the methods of the class and is accessed using the instance of the class. Each instance of the class has its own copy of the instance attributes.
Instance attributes are used to store data that is unique to each instance of a class. They can have different values for different instances of the same class. Instance attributes define the state of an object and can be accessed and modified using the dot notation.
Here’s an example to illustrate instance attributes in Python:
```python
class Car:
def __init__(self, brand, model):
self.brand = brand # instance attribute
self.model = model # instance attribute
def display_info(self):
print(f"Brand: {self.brand}, Model: {self.model}")
car1 = Car(“Toyota”, “Camry”)
car2 = Car(“Honda”, “Civic”)
car1.display_info() # Output: Brand: Toyota, Model: Camry
car2.display_info() # Output: Brand: Honda, Model: Civic
~~~
In the example above, the brand and model variables are instance attributes of the Car class. Each instance of the Car class (car1 and car2) has its own copy of these attributes, which can be accessed using self.brand and self.model respectively.
TeamTreeHouse Notes:
* Attributes = the name in Python for the properties of an object
* Instance attributes = attributes that are created when an object is instantiated
* Method = a function inside of a class
* Dunder method = a nickname for a method that has double underscores before and after its name (Ex: __init__)
what is \_\_init\_\_ in python?
In Python, \_\_init\_\_ is a special method, also known as the constructor, that is automatically called when an object of a class is created. It is used to initialize the attributes of the object and perform any other setup or initialization tasks.
The \_\_init\_\_ method is defined within a class and takes the self parameter, which represents the instance of the class being created. It can also take additional parameters that are used to initialize the attributes of the object.
Here’s an example to illustrate the usage of \_\_init\_\_:
```python
class Car:
def __init__(self, brand, model):
self.brand = brand
self.model = model
def display_info(self):
print(f"Brand: {self.brand}, Model: {self.model}")
car1 = Car(“Toyota”, “Camry”)
car1.display_info() # Output: Brand: Toyota, Model: Camry
~~~
In the example above, the Car class has an \_\_init\_\_ method that takes brand and model as parameters. Inside the \_\_init\_\_ method, the attributes self.brand and self.model are initialized with the values passed to the constructor.
When car1 = Car("Toyota", "Camry") is executed, the \_\_init\_\_ method is automatically called with self set to car1, and the attributes brand and model are set to “Toyota” and “Camry” respectively.
The \_\_init\_\_ method allows you to set up the initial state of an object and perform any necessary initialization tasks before using the object further. It is a common practice to define the \_\_init\_\_ method in Python classes to ensure that objects are properly initialized when created.
What is \_\_init\_\_ in python?
In Python, \_\_init\_\_ is a special method, also known as the constructor, that is automatically called when an object of a class is created. It is used to initialize the attributes of the object and perform any other setup or initialization tasks.
The \_\_init\_\_ method is defined within a class and takes the self parameter, which represents the instance of the class being created. It can also take additional parameters that are used to initialize the attributes of the object.
Here’s an example to illustrate the usage of \_\_init\_\_:
```python
class Car:
def __init__(self, brand, model):
self.brand = brand
self.model = model
def display_info(self):
print(f"Brand: {self.brand}, Model: {self.model}")
car1 = Car(“Toyota”, “Camry”)
car1.display_info() # Output: Brand: Toyota, Model: Camry
~~~
In the example above, the Car class has an \_\_init\_\_ method that takes brand and model as parameters. Inside the \_\_init\_\_ method, the attributes self.brand and self.model are initialized with the values passed to the constructor.
When car1 = Car("Toyota", "Camry") is executed, the \_\_init\_\_ method is automatically called with self set to car1, and the attributes brand and model are set to “Toyota” and “Camry” respectively.
The \_\_init\_\_ method allows you to set up the initial state of an object and perform any necessary initialization tasks before using the object further. It is a common practice to define the \_\_init\_\_ method in Python classes to ensure that objects are properly initialized when created.
What is Dunder Init?
“Dunder init” is a shorthand term for the special method \_\_init\_\_ in Python. “Dunder” is derived from “double underscore,” which is represented by the character \_\_ surrounding the method name.
The \_\_init\_\_ method is a special method in Python classes that serves as the constructor. It is automatically called when an object of a class is created, allowing you to initialize the object’s attributes and perform any necessary setup or initialization tasks.
Here’s an example to demonstrate the usage of \_\_init\_\_ (dunder init):
```python
class Car:
def __init__(self, brand, model):
self.brand = brand
self.model = model
def display_info(self):
print(f"Brand: {self.brand}, Model: {self.model}")
car1 = Car(“Toyota”, “Camry”)
car1.display_info() # Output: Brand: Toyota, Model: Camry
~~~
In the example above, \_\_init\_\_ is the dunder init method of the Car class. It takes self (representing the instance of the class) as the first parameter, followed by any additional parameters (brand and model in this case).
When car1 = Car("Toyota", "Camry") is executed, the dunder init method \_\_init\_\_ is automatically called with self set to car1 and brand and model set to “Toyota” and “Camry” respectively. Inside the \_\_init\_\_ method, the attributes self.brand and self.model are initialized with these values.
Using dunder methods like \_\_init\_\_ allows you to define the behavior of your objects at specific moments or when certain operations are performed. They provide a way to customize the behavior of Python classes to suit your needs.
Explain the following codes:
One is:
~~~
class Pet():
legs: 4
ears: 2
tail: 1
def \_\_init\_\_(self, kind, breed, age):
self.kind = kind
self.breed = breed
self.age = age
pet_1 = Pet(‘cat’, ‘indian’, 2)
pet_2 = Pet(‘dog’, ‘german’, 1)
print(f’Pet 1 is a {pet_1.kind} of {pet_1.breed} breed and is {pet_1.age} years old’)
print(f’Pet 2 is a {pet_2.kind} of {pet_2.breed} breed and is {pet_2.age} years old’)
~~~
And Two is:
class Car():
wheels = 4
doors = 2
engine = True
def \_\_init\_\_(self, model, year, make='VW Group'):
self.make = make
self.model = model
self.year = year
car_one = Car('Vento', 2014)
car_two = Car('A4', 2024, 'Audii')
print(f'Car One: {car_one.doors}')
print(id(car_one.doors))
print(f'Car Two: {car_two.doors}')
print(id(car_two.doors))
print(f'Car Global: {Car.doors}')
print(id(Car.doors))
print(f'The car one is {car_one.make} {car_one.model} {car_one.year}')
print(f'The car two is {car_two.make} {car_two.model} {car_two.year}')
Sure! Let’s go through each code snippet and explain what it does.
Code Snippet One:
```python
class Pet():
legs: 4
ears: 2
tail: 1
def \_\_init\_\_(self, kind, breed, age):
self.kind = kind
self.breed = breed
self.age = age
pet_1 = Pet(‘cat’, ‘indian’, 2)
pet_2 = Pet(‘dog’, ‘german’, 1)
print(f’Pet 1 is a {pet_1.kind} of {pet_1.breed} breed and is {pet_1.age} years old’)
print(f’Pet 2 is a {pet_2.kind} of {pet_2.breed} breed and is {pet_2.age} years old’)
~~~
Explanation:
1. The code defines a class named Pet.
2. Inside the class, there are class attributes legs, ears, and tail which are set to the specified values. These attributes are shared among all instances of the class.
3. The \_\_init\_\_ method is defined as the constructor. It takes parameters kind, breed, and age, and initializes instance attributes self.kind, self.breed, and self.age with the passed values.
4. Two instances of the Pet class, pet_1 and pet_2, are created using different arguments.
5. The print statements display information about the pets, accessing their attributes using dot notation (pet_1.kind, pet_1.breed, pet_1.age, etc.).
Output:
Pet 1 is a cat of indian breed and is 2 years old Pet 2 is a dog of german breed and is 1 years old
Code Snippet Two:
```python
class Car():
wheels = 4
doors = 2
engine = True
def \_\_init\_\_(self, model, year, make='VW Group'):
self.make = make
self.model = model
self.year = year
car_one = Car(‘Vento’, 2014)
car_two = Car(‘A4’, 2024, ‘Audii’)
print(f’Car One: {car_one.doors}’)
print(id(car_one.doors))
print(f’Car Two: {car_two.doors}’)
print(id(car_two.doors))
print(f’Car Global: {Car.doors}’)
print(id(Car.doors))
print(f’The car one is {car_one.make} {car_one.model} {car_one.year}’)
print(f’The car two is {car_two.make} {car_two.model} {car_two.year}’)
~~~
Explanation:
1. The code defines a class named Car.
2. Inside the class, there are class attributes wheels, doors, and engine which are set to the specified values. These attributes are shared among all instances of the class.
3. The \_\_init\_\_ method is defined as the constructor. It takes parameters model, year, and an optional parameter make with a default value of 'VW Group'. It initializes instance attributes self.make, self.model, and self.year with the passed values.
4. Two instances of the Car class, car_one and car_two, are created using different arguments.
5. The print statements display information about the cars, accessing their attributes using dot notation (car_one.doors, car_one.make, etc.).
6. The id() function is used to display the
memory address of the doors attribute, demonstrating that it refers to the same object across instances and the class.
Output:
Car One: 2 <id1> Car Two: 2 <id1> Car Global: 2 <id1> The car one is VW Group Vento 2014 The car two is Audii A4 2024
Note: The <id1> placeholder represents the memory address of the doors attribute, which will be different each time the code is executed.
Challenge 1: Create a class called Panda. Inside your class, create two class attributes. One called species set to ‘Ailuropoda melanoleuca’ and another called food set to ‘bamboo’.
Challenge 2: Add an __init__ method to your class. It should only take the self argument. Inside the method, create an instance attribute called is_hungry and set it equal to True.
Challenge 1: Creating the Panda class with class attributes.
```python
class Panda:
species = ‘Ailuropoda melanoleuca’
food = ‘bamboo’
~~~
In the above code, we define a class called Panda. Inside the class, we create two class attributes: species set to the string 'Ailuropoda melanoleuca' and food set to the string 'bamboo'.
Challenge 2: Adding the __init__ method and instance attribute.
```python
class Panda:
species = ‘Ailuropoda melanoleuca’
food = ‘bamboo’
def \_\_init\_\_(self):
self.is_hungry = True ~~~
In the updated code, we add the \_\_init\_\_ method to the Panda class. The \_\_init\_\_ method takes only the self argument, as it is always required in a method within a class. Inside the \_\_init\_\_ method, we create an instance attribute called is_hungry and set it to True.
Now, when you create an instance of the Panda class, the is_hungry attribute will be automatically initialized to True.
Here’s an example usage:
```python
panda = Panda()
print(panda.species) # Output: Ailuropoda melanoleuca
print(panda.food) # Output: bamboo
print(panda.is_hungry) # Output: True
~~~
In the example above, we create an instance of the Panda class called panda. We can access the class attributes species and food using the instance (panda.species and panda.food) and the instance attribute is_hungry (panda.is_hungry).
Explain the following code:
class Car():
wheels = 4
doors = 2
engine = True
def \_\_init\_\_(self, model, year, make='VW Group'):
self.make = make
self.model = model
self.year = year
self.gas = 100
self.is_moving = False
def stop(self):
if self.is_moving:
print("The Car has Stopped!")
self.is_moving = False
else:
print("The Car has already Stopped!!")
def go(self, speed):
if self.use_gas():
if not self.is_moving:
print("The Car starts is Moving")
self.is_moving = True
print(f'The car is going at {speed}')
else:
print("You have run out of gas")
self.stop()
def use_gas(self):
self.gas -= 50
if self.gas <= 0:
return False
else:
return True
car_one = Car('Vento', 2014)
car_two = Car('A4', 2024, 'Audii')
car_one.stop()
car_one.go(120)
car_one.go('fast')
car_one.stop()
car_one.stop()
car_one.go(100)
The code provided defines a class Car and demonstrates its usage. Let’s go through the code and explain its functionality step by step:
```python
class Car():
wheels = 4
doors = 2
engine = True
def \_\_init\_\_(self, model, year, make='VW Group'):
self.make = make
self.model = model
self.year = year
self.gas = 100
self.is_moving = False ~~~
- The code defines a class named
Car. - Inside the class, there are class attributes
wheels,doors, andenginewhich are set to their respective values. These attributes are shared among all instances of the class. - The
\_\_init\_\_method is defined as the constructor. It takes parametersmodel,year, and an optional parametermakewith a default value of'VW Group'. - Inside the
\_\_init\_\_method, there are instance attributesself.make,self.model,self.year,self.gas, andself.is_moving. These attributes store specific data for each instance of the class.
```python
def stop(self):
if self.is_moving:
print(“The Car has Stopped!”)
self.is_moving = False
else:
print(“The Car has already Stopped!!”)
~~~
- The
stopmethod is defined within theCarclass. - It checks the
is_movingattribute of the instance to determine if the car is already moving. - If the car is moving (
self.is_movingisTrue), it prints a message indicating that the car has stopped and updatesself.is_movingtoFalse. - If the car is not moving (
self.is_movingisFalse), it prints a message indicating that the car has already stopped.
```python
def go(self, speed):
if self.use_gas():
if not self.is_moving:
print(“The Car starts is Moving”)
self.is_moving = True
print(f’The car is going at {speed}’)
else:
print(“You have run out of gas”)
self.stop()
~~~
- The
gomethod is defined within theCarclass. - It first checks if there is enough gas by calling the
use_gasmethod. - If there is enough gas (
self.use_gas()returnsTrue), it checks if the car is not already moving (self.is_movingisFalse). - If the car is not moving, it prints a message indicating that the car has started moving and updates
self.is_movingtoTrue. - It then prints a message indicating the speed at which the car is going, using the
speedparameter passed to the method. - If there is not enough gas (
self.use_gas()returnsFalse), it prints a message indicating that the car has run out of gas and calls thestopmethod to stop the car.
```python
def use_gas(self):
self.gas -= 50
if self.gas <= 0:
return False
else:
return True
~~~
- The
use_gasmethod is defined within theCarclass. - It subtracts 50 from the
self.gasattribute to simulate gas consumption. - It then checks if the gas level is below or equal to 0. If it is, it returns
Falseto indicate that there is not enough gas. - Otherwise
, if the gas level is above 0, it returns True to indicate that there is enough gas.
```python
car_one = Car(‘Vento’, 2014)
car_two = Car(‘A4’, 2024, ‘Audii’)
car_one.stop()
car_one.go(120)
car_one.go(‘fast’)
car_one.stop()
car_one.stop()
car_one.go(100)
~~~
- Two instances of the
Carclass,car_oneandcar_two, are created with different arguments passed to the constructor. - Method calls are made on the
car_oneinstance to stop the car (car_one.stop()), go at a speed of 120 (car_one.go(120)), go at a speed of ‘fast’ (car_one.go('fast')), stop the car again (car_one.stop()), stop the car again (car_one.stop()), and finally go at a speed of 100 (car_one.go(100)).
The code demonstrates the usage of class attributes, instance attributes, methods, and instance initialization. It simulates the behavior of a car object, such as starting, stopping, and consuming gas.
Challenge 1: Using your Panda class, add two arguments to your class in the __init__ method called name and age. Set the values inside of the __init__ method using self.
class Panda:
species = 'Ailuropoda melanoleuca'
food = 'bamboo'
def \_\_init\_\_(self):
self.is_hungry = True
Challenge 2:
Create a method called eat. It should only take self as an argument. Inside of the method, set the is_hungry attribute to False, since the Panda will no longer be hungry when it eats. Also, return a string that says ‘Bao Bao eats bamboo.’ where ‘Bao Bao’ is the name attribute and ‘bamboo’ is the food attribute.
Challenge 3:
Create another method called check_if_hungry that also only takes self. Inside of the method, if the is_hungry attribute is True, then call the eat method.
Certainly! Here’s the modified code that addresses all three challenges:
```python
class Panda:
species = ‘Ailuropoda melanoleuca’
food = ‘bamboo’
def \_\_init\_\_(self, name, age):
self.name = name
self.age = age
self.is_hungry = True
def eat(self):
self.is_hungry = False
return f'{self.name} eats {self.food}.'
def check_if_hungry(self):
if self.is_hungry:
self.eat()
panda = Panda(‘Bao Bao’, 5)
print(panda.check_if_hungry())
~~~
In the modified code:
Challenge 1: The \_\_init\_\_ method of the Panda class now accepts name and age as arguments and initializes the instance attributes self.name, self.age, and self.is_hungry with the respective values.
Challenge 2: The eat method sets self.is_hungry to False to indicate that the panda is no longer hungry. It returns a string using the instance attribute self.name and the class attribute self.food.
Challenge 3: The check_if_hungry method checks if the panda is hungry (self.is_hungry is True). If so, it calls the eat method to feed the panda.
The example usage prints the result of calling the check_if_hungry method on the panda instance.
Output:
Bao Bao eats bamboo.
Now, the code correctly initializes the name and age attributes, allows the panda to eat, and checks if it is hungry before feeding it.
What is class attribute and what is instance attribute in Python?
In Python, class attributes and instance attributes are two types of attributes that can be defined in a class. They serve different purposes and have different scopes and visibility within the class.
Class Attribute:
- Class attributes are attributes that are shared among all instances of a class.
- They are defined within the class body but outside of any methods.
- Class attributes have the same value for all instances of the class.
- They are accessed using the class name or through an instance of the class.
- Class attributes are typically used to define properties or characteristics that are common to all instances of the class.
Here’s an example of a class attribute:
```python
class Car:
wheels = 4 # Class attribute
car1 = Car()
car2 = Car()
print(car1.wheels) # Output: 4
print(car2.wheels) # Output: 4
print(Car.wheels) # Output: 4
~~~
In the above code, wheels is a class attribute of the Car class. It is shared by all instances of the class. It can be accessed using the class name (Car.wheels) or through an instance (car1.wheels or car2.wheels).
Instance Attribute:
- Instance attributes are attributes that belong to individual instances of a class.
- They are defined within the methods of a class, primarily in the \_\_init\_\_ method.
- Instance attributes have different values for each instance of the class.
- They are accessed using the instance name.
- Instance attributes are typically used to represent properties or characteristics that vary from instance to instance.
Here’s an example of an instance attribute:
```python
class Car:
def __init__(self, make, model):
self.make = make # Instance attribute
self.model = model # Instance attribute
car1 = Car(“Toyota”, “Camry”)
car2 = Car(“Honda”, “Civic”)
print(car1.make) # Output: Toyota
print(car1.model) # Output: Camry
print(car2.make) # Output: Honda
print(car2.model) # Output: Civic
~~~
In the above code, make and model are instance attributes of the Car class. Each instance (car1 and car2) has its own unique values for these attributes. They are accessed using the instance names (car1.make, car1.model, car2.make, car2.model).
To summarize, class attributes are shared among all instances of a class and have the same value for each instance. Instance attributes, on the other hand, belong to individual instances and have different values for each instance.
car_one = Car('Ford','Model T')
In the code above, car_one is an \_\_\_\_\_\_\_ of our Car class.
In the code car_one = Car('Ford', 'Model T'), car_one is an instance of our Car class.
Explanation:
When we create an object using the class, it is referred to as an instance of that class. In this case, Car('Ford', 'Model T') creates an instance of the Car class with the make 'Ford' and model 'Model T'. We assign this instance to the variable car_one.
Instances have their own set of attributes and can access both instance attributes and class attributes defined within the class. They can also invoke methods defined within the class.
In the given code, car_one represents a specific car object, an instance of the Car class, with its own unique attributes and behavior.
What is the difference between method, function, class attribute, instance attribute in Python?
In Python, there are several terms that describe different concepts within the language. Here’s an explanation of the differences between methods, functions, class attributes, and instance attributes:
Method:
- A method is a function that is defined within a class and is associated with an instance of that class or the class itself.
- Methods are defined within the class body and have access to the instance or class they belong to through the self parameter (for instance methods) or the class name (for class methods and static methods).
- Methods can operate on the data stored in the instance or class and can modify or retrieve instance attributes or invoke other methods.
- Example: def my_method(self, arg1, arg2): ...
Function:
- A function is a block of reusable code that performs a specific task and can be called from anywhere in the code.
- Functions can be defined outside of any class and can be used independently without any association with specific instances or classes.
- Functions typically take input arguments, perform some operations, and optionally return a result.
- Example: def my_function(arg1, arg2): ...
Class Attribute:
- A class attribute is a variable that is defined within a class and is shared among all instances of that class.
- Class attributes are defined within the class body but outside of any methods.
- They have the same value for all instances of the class and can be accessed using the class name or through instances of the class.
- Class attributes typically represent properties or characteristics that are common to all instances of the class.
- Example: attribute = value
Instance Attribute:
- An instance attribute is a variable that belongs to a specific instance of a class.
- Instance attributes are defined within the methods of a class, primarily in the \_\_init\_\_ method, and are initialized when an instance is created.
- They have different values for each instance of the class and can be accessed and modified using the instance name.
- Instance attributes typically represent properties or characteristics that vary from instance to instance.
- Example: self.attribute = value (inside \_\_init\_\_ or other instance methods)
To summarize:
- Methods are functions defined within a class that operate on instances or the class itself.
- Functions are standalone blocks of reusable code that can be called from anywhere.
- Class attributes are variables shared among all instances of a class.
- Instance attributes are variables that belong to specific instances of a class.
In the following code:
class Car:
# Class Attributes
wheels = 4
doors = 2
engine = True
# The Initializer
def \_\_init\_\_(self, model, year, make='Ford', gas=100):
# Instance Attributes
self.make = make
self.model = model
self.year = year
self.gas = gas
# instance attributes don't have
# to be passed in
self.is_moving = False
def \_\_str\_\_(self):
return f'{self.make} {self.model} {self.year}'
def use_gas(self):
self.gas -= 50
if self.gas <= 0:
return False
return True
def stop(self):
if self.is_moving:
print('The car has stopped.')
self.is_moving = False
else:
print('The car has already stopped.')
def go(self, speed):
if self.use_gas():
if not self.is_moving:
print('The car starts moving.')
self.is_moving = True
print(f'The car is going {speed}.')
else:
print("You've run out of gas!")
self.stop()
car_one = Car('Model T', 1908)
car_two = Car('Phantom', 2020, 'Rolls Royce')
print(dir(car_one))
print(car_one)
print(str(car_one))
Explain dir function and str method.
The dir function and the \_\_str\_\_ method are both related to object-oriented programming in Python and provide information about objects.
-
dir(object):
Thedirfunction is a built-in Python function that returns a sorted list of attributes and methods of the specified object. When called with an object as its argument,dirreturns a list of names that are defined in the object’s namespace.
In the given code, print(dir(car_one)) outputs a sorted list of attributes and methods for the car_one object. This includes both the attributes and methods inherited from the object class and the attributes and methods specific to the Car class.
-
\_\_str\_\_method:
The\_\_str\_\_method is a special method in Python classes that defines the string representation of an object. It is called by thestr()function and theprint()function to get a printable string representation of the object.
In the given code, the Car class defines its own \_\_str\_\_ method:
```python
def __str__(self):
return f’{self.make} {self.model} {self.year}’
~~~
This method returns a formatted string that represents the car’s make, model, and year. When print(car_one) or str(car_one) is called, it invokes the \_\_str\_\_ method of the car_one object, which returns the desired string representation.
Therefore, print(car_one) and print(str(car_one)) both output the string representation of the car_one object, which in this case would be something like: “Ford Model T 1908”.
What does iter method (dunder iter) do in Python?
The \_\_iter\_\_ method, also known as the dunder iter method, is a special method in Python classes that enables an object to be iterable. It allows an object to define its own iteration behavior when used in a for loop or when the iter() function is called on the object.
The \_\_iter\_\_ method should return an iterator object. An iterator is an object that implements the \_\_next\_\_ method, which returns the next item in the iteration. If there are no more items, the \_\_next\_\_ method should raise the StopIteration exception.
Here’s a simple example to illustrate the usage of \_\_iter\_\_:
```python
class MyIterable:
def __init__(self, data):
self.data = data
def \_\_iter\_\_(self):
# Returning an iterator object
return iter(self.data)
my_iterable = MyIterable([1, 2, 3, 4, 5])
for item in my_iterable:
print(item)
~~~
In the example, the MyIterable class defines the \_\_iter\_\_ method, which simply returns an iterator object using the iter() function and passing the self.data list as an argument. The iter() function converts the list into an iterator.
When the for loop is executed, it calls the iter() function on the my_iterable object. This, in turn, invokes the \_\_iter\_\_ method, which returns an iterator. The for loop then calls the \_\_next\_\_ method on the iterator repeatedly until it encounters the StopIteration exception.
In summary, the \_\_iter\_\_ method allows objects to be iterated over using the Python iteration protocol, enabling them to be used in for loops and other iterable contexts.
Explain the following code:
class Car:
# Class Attributes
wheels = 4
doors = 2
engine = True
# The Initializer
def \_\_init\_\_(self, model, year, make='Ford', gas=100):
# Instance Attributes
self.make = make
self.model = model
self.year = year
self.gas = gas
# instance attributes don't have
# to be passed in
self.is_moving = False
def \_\_str\_\_(self):
return f'{self.make} {self.model} {self.year}'
def use_gas(self):
self.gas -= 50
if self.gas <= 0:
return False
return True
def stop(self):
if self.is_moving:
print('The car has stopped.')
self.is_moving = False
else:
print('The car has already stopped.')
def go(self, speed):
if self.use_gas():
if not self.is_moving:
print('The car starts moving.')
self.is_moving = True
print(f'The car is going {speed}.')
else:
print("You've run out of gas!")
self.stop()
class Dealership:
def \_\_init\_\_(self):
self.cars = ["Ford Fusion", "Honda Civic", "Dodge Dakota"]
def \_\_iter\_\_(self):
yield from self.cars
car_one = Car('Model T', 1908)
my_dealership = Dealership()
for car in my_dealership:
print(car)
Explain dunder iter and also what does yield from means?
In the provided code, there are two classes: Car and Dealership. The Dealership class implements the \_\_iter\_\_ method using the yield from syntax. Let’s explain the concepts involved:
-
\_\_iter\_\_method:
The\_\_iter\_\_method is a special method in Python classes that allows an object to be an iterable. When defined in a class, it should return an iterator object. In this case, the\_\_iter\_\_method is defined in theDealershipclass. -
yield fromstatement:
Theyield fromstatement is used within the\_\_iter\_\_method to delegate the iteration to another iterable, in this case, theself.carslist. It simplifies the process of creating iterators by allowing one iterable to yield values from another iterable. Theyield fromstatement was introduced in Python 3.3 as a way to delegate to a subgenerator or another iterable.
In the given code, the Dealership class has a list of cars stored in the self.cars attribute. The \_\_iter\_\_ method uses the yield from statement to delegate the iteration to the self.cars list. This means that when the for loop iterates over an instance of the Dealership class, it will yield each car from the self.cars list.
Here’s a breakdown of the code execution:
- An instance of the
Dealershipclass,my_dealership, is created. - The
forloop iterates overmy_dealership. - Since
my_dealershiphas the\_\_iter\_\_method defined, it is considered iterable. - The
\_\_iter\_\_method is called, and it usesyield from self.carsto yield each car from theself.carslist. - The
forloop receives each car value and prints it.
In summary, the \_\_iter\_\_ method with yield from allows the Dealership class to be iterable, and the for loop in the code iterates over the cars in the dealership and prints each car’s name.
Explain the following code:
class Car:
# Class Attributes
wheels = 4
doors = 2
engine = True
# The Initializer
def \_\_init\_\_(self, model, year, make='Ford', gas=100):
# Instance Attributes
self.make = make
self.model = model
self.year = year
self.gas = gas
# instance attributes don't have
# to be passed in
self.is_moving = False
def \_\_str\_\_(self):
return f'{self.make} {self.model} {self.year}'
def use_gas(self):
self.gas -= 50
if self.gas <= 0:
return False
return True
def stop(self):
if self.is_moving:
print('The car has stopped.')
self.is_moving = False
else:
print('The car has already stopped.')
def go(self, speed):
if self.use_gas():
if not self.is_moving:
print('The car starts moving.')
self.is_moving = True
print(f'The car is going {speed}.')
else:
print("You've run out of gas!")
self.stop()
class Dealership:
def \_\_init\_\_(self):
self.cars = []
def \_\_iter\_\_(self):
yield from self.cars
def add_car(self, car):
self.cars.append(car)
car_one = Car('Model T', 1908)
car_two = Car('Fusion', 1990)
car_three = Car('Fiesta', 2000)
my_dealership = Dealership()
my_dealership.add_car(car_one)
my_dealership.add_car(car_two)
my_dealership.add_car(car_three)
for car in my_dealership:
print(car)
Also explain what will happen if:
def \_\_str\_\_(self):
return f'{self.make} {self.model} {self.year}
is removed from the above code, what will it return and why?
The provided code includes two classes: Car and Dealership. The Car class represents a car object with various attributes and methods, and the Dealership class represents a dealership that can hold multiple cars.
In the code, car_one, car_two, and car_three are instances of the Car class, and they are added to the my_dealership instance of the Dealership class using the add_car method.
The Dealership class has the \_\_iter\_\_ method implemented using yield from self.cars. This makes it iterable, allowing the for loop to iterate over the cars stored in the self.cars list.
When the for loop is executed with for car in my_dealership, it calls the \_\_iter\_\_ method on my_dealership, which uses yield from to yield each car from the self.cars list. The cars are then printed inside the for loop.
Now, let’s discuss what would happen if the \_\_str\_\_ method is removed from the Car class:
```python
def __str__(self):
return f’{self.make} {self.model} {self.year}’
~~~
The \_\_str\_\_ method is responsible for providing a string representation of the Car object. When it is removed, the default string representation provided by the object class is used. The default representation will include the class name and the memory address of the object, something like <\_\_main\_\_.Car object at 0x00000123456789>, where 0x00000123456789 is the memory address.
So, without the \_\_str\_\_ method, when the print(car) statement is executed in the for loop, it will print the default string representation of the Car object, displaying the class name and memory address.
Create the code with following condition:
- Create a class with attributes
- Definie init method
- Define str
- Create another class for library
- Define init in the new class with an empty
- Create empty list [] within the init
- Define iter in the new class
- Use yield within the iter
- define add to library
- create append to add to the empty list
- Call out above functions and add items to the list
- Use for loop to print the items in the list.
Example 1:
~~~
class Game:
console: ‘Playstation’
kind: ‘AAA Game’
def \_\_init\_\_(self, title, developer):
self.title = title
self.developer = developer
def \_\_str\_\_(self):
return f'{self.developer} {self.title}'
class Game_library:
def __init__(self):
self.games = []
def \_\_iter\_\_(self):
yield from self.games
def add_games(self, game):
self.games.append(game)
game1 = Game(‘GTA 5’, ‘Rockstar Games’)
game2 = Game(‘Sonic’, ‘Sega’)
game3 = Game(‘Hogwarts Legacy’, ‘Warner Bros.’)
game_library = Game_library()
game_library.add_games(game1)
game_library.add_games(game2)
game_library.add_games(game3)
for game in game_library:
print(game)
~~~
Example 2:
class Candy:
def \_\_init\_\_(self, name, color):
self.name = name
self.color = color
def \_\_str\_\_(self):
return f'{self.color} {self.name}'
class CandyStore:
def \_\_init\_\_(self):
self.candies = []
def \_\_iter\_\_(self):
yield from self.candies
def add_candy(self, candy):
self.candies.append(candy)
nerds = Candy('Nerds', 'Multi')
chocolate = Candy("Hersey's Bar", 'Brown')
my_store = CandyStore()
my_store.add_candy(nerds)
my_store.add_candy(chocolate)
for candy in my_store:
print(candy)
What is dunder equals? What does it do?
In Python, “dunder” is a shorthand term for “double underscore.” Dunder methods, also known as magic methods or special methods, are a set of predefined methods in Python classes that enable you to define the behavior of objects for built-in operations and syntax.
“Dunder equals” refers to the \_\_eq\_\_ method, which is a dunder method used for equality comparison. It allows objects to define their own custom equality logic when using the == operator.
The \_\_eq\_\_ method takes two parameters: self (representing the current instance) and other (representing the object being compared to). It should return True if the objects are considered equal according to the defined equality logic, and False otherwise.
Here’s an example of how to define the \_\_eq\_\_ method in a class:
```python
class MyClass:
def __init__(self, value):
self.value = value
def \_\_eq\_\_(self, other):
if isinstance(other, MyClass):
return self.value == other.value
return False ~~~
In this example, the MyClass class has an instance attribute value. The \_\_eq\_\_ method is defined to compare the value attribute of two MyClass objects. It first checks if the other object is an instance of MyClass using isinstance(other, MyClass). If it is, the method compares the value attributes of both objects. If they are equal, it returns True; otherwise, it returns False.
By defining the \_\_eq\_\_ method, you can customize the behavior of the equality comparison operator == for objects of your class.
Explain the following code:
class Car:
# Class Attributes
wheels = 4
doors = 2
engine = True
# The Initializer
def \_\_init\_\_(self, model, year, make='Ford', gas=100):
# Instance Attributes
self.make = make
self.model = model
self.year = year
self.gas = gas
# instance attributes don't have
# to be passed in
self.is_moving = False
def \_\_str\_\_(self):
return f'{self.make} {self.model} {self.year}'
def \_\_eq\_\_(self, other):
return self.make == other.make and self.model == other.model
def use_gas(self):
self.gas -= 50
if self.gas <= 0:
return False
return True
def stop(self):
if self.is_moving:
print('The car has stopped.')
self.is_moving = False
else:
print('The car has already stopped.')
def go(self, speed):
if self.use_gas():
if not self.is_moving:
print('The car starts moving.')
self.is_moving = True
print(f'The car is going {speed}.')
else:
print("You've run out of gas!")
self.stop()
class Dealership:
def \_\_init\_\_(self):
self.cars = []
def \_\_iter\_\_(self):
yield from self.cars
def add_car(self, car):
self.cars.append(car)
car_one = Car('Model T', 1908)
car_two = Car('Fusion', 1990)
car_three = Car('Fusion', 2000)
if car_one == car_two:
print('equal')
else:
print('not equal')
if car_two == car_three:
print('equal')
else:
print('not equal')
The provided code demonstrates the use of the Car and Dealership classes to create car objects and compare their equality. Let’s break down the code:
- The
Carclass:- It represents a car and has class attributes such as
wheels,doors, andengine. - The
\_\_init\_\_method is the initializer that sets instance attributes for the car object, includingmake,model,year,gas, andis_moving. - The
\_\_str\_\_method provides a string representation of the car object. - The
\_\_eq\_\_method compares two car objects for equality based on theirmakeandmodelattributes. - The
use_gasmethod decreases thegasattribute by 50 units and checks if there is enough gas. - The
stopmethod prints a message when the car stops. - The
gomethod checks if there is enough gas, starts the car if it’s not moving, and prints the speed.
- It represents a car and has class attributes such as
- The
Dealershipclass:- It represents a dealership that can hold multiple cars.
- The
\_\_init\_\_method initializes an empty listcarsas an instance attribute. - The
\_\_iter\_\_method enables iteration over thecarslist using theyield fromstatement. - The
add_carmethod adds a car to thecarslist.
- Car instances and comparison:
- Three car instances are created:
car_one,car_two, andcar_three, with different attributes. - The code then compares
car_onewithcar_twofor equality using the==operator. Since they have different makes and models, the output will be “not equal,” and it will be printed. - Next,
car_twois compared withcar_three. As they have the same make and model, the output will be “equal,” and it will be printed.
- Three car instances are created:
In summary, the code demonstrates the usage of class attributes, instance attributes, methods, and the yield from statement in the context of car objects and a car dealership. It also showcases how the \_\_eq\_\_ method can be implemented to define custom equality comparison logic for objects of the Car class.
Challenge 1: Create a __str__ method for this book class. Return a string with the author and title of the book. Ex: John Green, Paper Towns
books.py
class Book:
def \_\_init\_\_(self, author, title):
self.author = author
self.title = title
bookcase.py
from book import Book
class BookCase:
def \_\_init\_\_(self):
self.books = []
def add_books(self, book):
self.books.append(book)
Challenge 2: Add a __eq__ method for this book class. It should check if the author and title of the book are the same and return true if they are and false if they aren’t.
Challenge 3: I’ve added a Bookcase class inside bookcase.py. It will hold some books in a list. Add a __iter__ method so I can loop through the books. Use yield from and the book list inside the method.
Answer to Challenge 1:
class Book:
def \_\_init\_\_(self, author, title):
self.author = author
self.title = title
def \_\_str\_\_(self):
return f'{self.author}, {self.title}'
Answer to Challenge 2:
class Book:
def \_\_init\_\_(self, author, title):
self.author = author
self.title = title
def \_\_str\_\_(self):
return f'{self.author}, {self.title}'
def \_\_eq\_\_(self, other):
return self.author == other.author and self.title == other.title
Answer to Challenge 3:
from book import Book
class BookCase:
def \_\_init\_\_(self):
self.books = []
def add_books(self, book):
self.books.append(book)
def \_\_iter\_\_(self):
yield from self.books
Instance attributes always have to be passed in when an instance is created.
True or False?
False.
Instance attributes in Python do not always have to be passed in when an instance is created. They can be initialized with default values within the \_\_init\_\_ method of a class. If a value is not provided during instance creation, the default value specified in the \_\_init\_\_ method will be used.
In the provided code, the Car class demonstrates this concept. It has an \_\_init\_\_ method with default values for the make and gas attributes:
```python
def __init__(self, model, year, make=’Ford’, gas=100):
# Instance Attributes
self.make = make
self.model = model
self.year = year
self.gas = gas
self.is_moving = False
~~~
In this case, when creating an instance of the Car class, if values for make and gas are not provided, the default values 'Ford' and 100 will be used, respectively.
For example:
```python
car_one = Car(‘Model T’, 1908)
~~~
In this case, since make and gas are not explicitly provided, the default values 'Ford' and 100 will be assigned to the respective instance attributes make and gas.
However, if desired, explicit values can be provided during instance creation to override the default values:
```python
car_two = Car(‘Phantom’, 2020, ‘Rolls Royce’, 75)
~~~
Here, the instance car_two has a different make and gas value compared to the default values specified in the \_\_init\_\_ method.False.
Instance attributes in Python do not always have to be passed in when an instance is created. They can be initialized with default values within the \_\_init\_\_ method of a class. If a value is not provided during instance creation, the default value specified in the \_\_init\_\_ method will be used.
In the provided code, the Car class demonstrates this concept. It has an \_\_init\_\_ method with default values for the make and gas attributes:
```python
def __init__(self, model, year, make=’Ford’, gas=100):
# Instance Attributes
self.make = make
self.model = model
self.year = year
self.gas = gas
self.is_moving = False
~~~
In this case, when creating an instance of the Car class, if values for make and gas are not provided, the default values 'Ford' and 100 will be used, respectively.
For example:
```python
car_one = Car(‘Model T’, 1908)
~~~
In this case, since make and gas are not explicitly provided, the default values 'Ford' and 100 will be assigned to the respective instance attributes make and gas.
However, if desired, explicit values can be provided during instance creation to override the default values:
```python
car_two = Car(‘Phantom’, 2020, ‘Rolls Royce’, 75)
~~~
Here, the instance car_two has a different make and gas value compared to the default values specified in the \_\_init\_\_ method.
There are two python files:
I) cards.py:
# class card
# hold a card
# matched or not?
# location
# \_\_eq\_\_
# \_\_str\_\_
class Card:
def \_\_init\_\_(self, word, location):
self.card = word
self.location = location
self.matched = False
def \_\_eq\_\_(self, other):
return self.card == other.card
def \_\_str\_\_(self):
return self.card
if \_\_name\_\_ == '\_\_main\_\_':
card1 = Card('egg', 'A1')
card2 = Card('egg', 'B1')
card3 = Card('hut', 'D4')
print(card1 == card2)
print(card2 == card3)
print(card1)
II) game.py:
from cards import Card
import random
class Game:
def \_\_init\_\_(self):
self.size = 4
self.card_options = ['Add', 'Boo', 'Cat', 'Dev',
'Egg', 'Far', 'Gum', 'Hut']
self.columns = ['A', 'B', 'C', 'D']
self.cards = []
self.locations = []
for column in self.columns:
for num in range(1, self.size+1):
self.locations.append(f'{column}{num}')
def set_cards(self):
used_locations = []
for word in self.card_options:
for i in range(2):
available_locations = set(self.locations) - set(used_locations)
random_location = random.choice(list(available_locations))
used_locations.append(random_location)
card = Card(word, random_location)
self.cards.append(card)
def create_row(self, num):
row = []
for column in self.columns:
for card in self.cards:
if card.location == f'{column}{num}':
if card.matched:
row.append(str(card))
else:
row.append(' ')
return row
def create_grid(self):
header = ' | ' + ' | '.join(self.columns) + ' |'
print(header)
for row in range(1, self.size + 1):
print_row = f'{row}| '
get_row = self.create_row(row)
print_row += ' | '.join(get_row) + ' |'
print(print_row)
if \_\_name\_\_ == '\_\_main\_\_':
game = Game()
game.set_cards()
game.cards[0].matched = True
game.cards[1].matched = True
game.cards[2].matched = True
game.cards[3].matched = True
game.create_grid()
Now explain this code step by step covering everything from scratch like you would explain a complete beginner.
Certainly! Let’s break down the code step by step, providing a more detailed explanation for each part.
cards.py:
This file contains the definition of the Card class, which represents an individual playing card in the game.
```python
class Card:
def __init__(self, word, location):
self.card = word
self.location = location
self.matched = False
def \_\_eq\_\_(self, other):
return self.card == other.card
def \_\_str\_\_(self):
return self.card ~~~
- The
Cardclass has three attributes:-
card: This attribute stores the word written on the card. -
location: This attribute represents the location of the card on the game grid. -
matched: This attribute is a boolean flag indicating whether the card has been matched with another card.
-
- The
\_\_init\_\_method is the constructor of theCardclass. It takes two parameters:wordandlocation. It initializes thecardattribute with the providedword, sets thelocationattribute, and initializesmatchedtoFalse. - The
\_\_eq\_\_method is used to compare two cards for equality. It takes another card object,other, as a parameter. It compares thecardattribute of the current card with thecardattribute of theothercard and returnsTrueif they are the same, andFalseotherwise. - The
\_\_str\_\_method is responsible for returning a string representation of the card. In this case, it simply returns the word written on the card.
Below the class definition, there is a section that demonstrates the usage of the Card class:
```python
if __name__ == ‘__main__’:
card1 = Card(‘egg’, ‘A1’)
card2 = Card(‘egg’, ‘B1’)
card3 = Card(‘hut’, ‘D4’)
print(card1 == card2) print(card2 == card3) print(card1) ~~~
- This section creates three instances of the
Cardclass:card1,card2, andcard3. Each card is initialized with a word and a location. - The first two
printstatements comparecard1withcard2andcard2withcard3using the==operator. Sincecard1andcard2have the same word (‘egg’), the first comparison returnsTrue. However,card2andcard3have different words (‘egg’ and ‘hut’), so the second comparison returnsFalse. - The last
printstatement prints the string representation ofcard1, which is the word ‘egg’.
game.py:
This file contains the definition of the Game class, which represents the overall game.
```python
from cards import Card
import random
class Game:
def __init__(self):
self.size = 4
self.card_options = [‘Add’, ‘Boo’, ‘Cat’, ‘Dev’, ‘Egg’, ‘Far’, ‘Gum’, ‘Hut’]
self.columns = [‘A’, ‘B’, ‘C’, ‘D’]
self.cards = []
self.locations = []
for column in self.columns:
for num in range(1, self.size + 1):
self.locations.append(f’{column}{num}’)
def set_cards(self):
used_locations = []
for word in self.card_options:
for i in range(2):
available_locations = set(self.locations) - set(used_locations)
random_location = random.choice(list(available_locations))
used_locations.append(random_location)
card = Card(word, random_location)
self.cards.append(card)
def create_row(self, num):
row = []
for column in self.columns:
for card in self.cards:
if card.location == f'{column}{num}':
if card.matched:
row.append(str(card))
else:
row.append(' ')
return row
def create_grid(self):
header = ' | ' + ' | '.join(self.columns) + ' |'
print(header)
for row in range(1, self.size + 1):
print_row = f'{row}| '
get_row = self.create_row(row)
print_row += ' | '.join(get_row) + ' |'
print(print_row) ~~~
- The
Gameclass has several attributes:-
size: This attribute represents the size of the game grid, indicating the number of rows and columns. -
card_options: This attribute is a list that stores the possible words that can appear on the cards. -
columns: This attribute is a list that stores the column labels for the game grid. -
cards: This attribute is a list that will store theCardobjects for the game. -
locations: This attribute is a list that will store the available locations on the game grid.
-
- The
\_\_init\_\_method is the constructor of theGameclass. It initializes the attributes of the class. In particular:- It sets
sizeto 4, indicating a 4x4 grid. - It defines
card_optionswith a list of eight words. - It sets
columnsas a list of four letters: ‘A’, ‘B’, ‘C’, and ‘D’. - It sets
cardsas an empty list to store theCardobjects. - It generates the list of
locationsby iterating over the columns and row numbers, creating a string representation for each location.
- It sets
- The
set_cardsmethod is responsible for setting up the cards for the game. It goes through each word in thecard_optionslist and randomly assigns two unique locations to each word. It creates aCardobject for each word and location combination, and appends it to thecardslist. - The
create_rowmethod takes a row number as a parameter and generates a list representing the contents of that row on the game grid. It iterates over each column and checks if there is a card at the current location. If there is a matched card, it appends the string representation of the card to the row list. Otherwise, it appends three spaces (‘ ‘) to indicate an empty spot. - The
create_gridmethod generates the entire game grid and prints it to the console. It starts by printing the header row, which consists of the column labels separated by vertical bars. Then, it iterates over each row and calls thecreate_rowmethod to generate the content for that row. It concatenates the row content and prints it.
Finally, at the bottom of the file, there is a section that demonstrates the usage of the Game class:
```python
if __name__ == ‘__main__’:
game = Game()
game.set_cards()
game.cards[0].matched = True
game.cards[1].matched = True
game.cards[2].matched = True
game.cards[3].matched = True
game.create_grid()
~~~
- This section creates an instance of the
Gameclass calledgame. - It
then calls the set_cards method to set up the cards for the game.
- Next, it manually marks the first four cards in the
cardslist as matched by setting theirmatchedattribute toTrue. - Finally, it calls the
create_gridmethod to generate and print the game grid, showing the matched cards and empty spots.
That’s a detailed explanation of the code! The provided code simulates a simple matching card game, where cards are represented by the Card class and the game itself is handled by the Game class.
There are two python files:
I) cards.py:
# class card
# hold a card
# matched or not?
# location
# \_\_eq\_\_
# \_\_str\_\_
class Card:
def \_\_init\_\_(self, word, location):
self.card = word
self.location = location
self.matched = False
def \_\_eq\_\_(self, other):
return self.card == other.card
def \_\_str\_\_(self):
return self.card
if \_\_name\_\_ == '\_\_main\_\_':
card1 = Card('egg', 'A1')
card2 = Card('egg', 'B1')
card3 = Card('hut', 'D4')
print(card1 == card2)
print(card2 == card3)
print(card1)
II) game.py:
from cards import Card
import random
class Game:
def \_\_init\_\_(self):
self.size = 4
self.card_options = ['Add', 'Boo', 'Cat', 'Dev',
'Egg', 'Far', 'Gum', 'Hut']
self.columns = ['A', 'B', 'C', 'D']
self.cards = []
self.locations = []
for column in self.columns:
for num in range(1, self.size+1):
self.locations.append(f'{column}{num}')
def set_cards(self):
used_locations = []
for word in self.card_options:
for i in range(2):
available_locations = set(self.locations) - set(used_locations)
random_location = random.choice(list(available_locations))
used_locations.append(random_location)
card = Card(word, random_location)
self.cards.append(card)
def create_row(self, num):
row = []
for column in self.columns:
for card in self.cards:
if card.location == f'{column}{num}':
if card.matched:
row.append(str(card))
else:
row.append(' ')
return row
def create_grid(self):
header = ' | ' + ' | '.join(self.columns) + ' |'
print(header)
for row in range(1, self.size + 1):
print_row = f'{row}| '
get_row = self.create_row(row)
print_row += ' | '.join(get_row) + ' |'
print(print_row)
if \_\_name\_\_ == '\_\_main\_\_':
game = Game()
game.set_cards()
game.cards[0].matched = True
game.cards[1].matched = True
game.cards[2].matched = True
game.cards[3].matched = True
game.create_grid()
Now explain this code step by step covering everything from scratch like you would explain a complete beginner.
Certainly! Let’s break down the code step by step, providing a more detailed explanation for each part.
cards.py:
This file contains the definition of the Card class, which represents an individual playing card in the game.
```python
class Card:
def __init__(self, word, location):
self.card = word
self.location = location
self.matched = False
def \_\_eq\_\_(self, other):
return self.card == other.card
def \_\_str\_\_(self):
return self.card ~~~
- The
Cardclass has three attributes:-
card: This attribute stores the word written on the card. -
location: This attribute represents the location of the card on the game grid. -
matched: This attribute is a boolean flag indicating whether the card has been matched with another card.
-
- The
\_\_init\_\_method is the constructor of theCardclass. It takes two parameters:wordandlocation. It initializes thecardattribute with the providedword, sets thelocationattribute, and initializesmatchedtoFalse. - The
\_\_eq\_\_method is used to compare two cards for equality. It takes another card object,other, as a parameter. It compares thecardattribute of the current card with thecardattribute of theothercard and returnsTrueif they are the same, andFalseotherwise. - The
\_\_str\_\_method is responsible for returning a string representation of the card. In this case, it simply returns the word written on the card.
Below the class definition, there is a section that demonstrates the usage of the Card class:
```python
if __name__ == ‘__main__’:
card1 = Card(‘egg’, ‘A1’)
card2 = Card(‘egg’, ‘B1’)
card3 = Card(‘hut’, ‘D4’)
print(card1 == card2) print(card2 == card3) print(card1) ~~~
- This section creates three instances of the
Cardclass:card1,card2, andcard3. Each card is initialized with a word and a location. - The first two
printstatements comparecard1withcard2andcard2withcard3using the==operator. Sincecard1andcard2have the same word (‘egg’), the first comparison returnsTrue. However,card2andcard3have different words (‘egg’ and ‘hut’), so the second comparison returnsFalse. - The last
printstatement prints the string representation ofcard1, which is the word ‘egg’.
game.py:
This file contains the definition of the Game class, which represents the overall game.
```python
from cards import Card
import random
class Game:
def __init__(self):
self.size = 4
self.card_options = [‘Add’, ‘Boo’, ‘Cat’, ‘Dev’, ‘Egg’, ‘Far’, ‘Gum’, ‘Hut’]
self.columns = [‘A’, ‘B’, ‘C’, ‘D’]
self.cards = []
self.locations = []
for column in self.columns:
for num in range(1, self.size + 1):
self.locations.append(f’{column}{num}’)
def set_cards(self):
used_locations = []
for word in self.card_options:
for i in range(2):
available_locations = set(self.locations) - set(used_locations)
random_location = random.choice(list(available_locations))
used_locations.append(random_location)
card = Card(word, random_location)
self.cards.append(card)
def create_row(self, num):
row = []
for column in self.columns:
for card in self.cards:
if card.location == f'{column}{num}':
if card.matched:
row.append(str(card))
else:
row.append(' ')
return row
def create_grid(self):
header = ' | ' + ' | '.join(self.columns) + ' |'
print(header)
for row in range(1, self.size + 1):
print_row = f'{row}| '
get_row = self.create_row(row)
print_row += ' | '.join(get_row) + ' |'
print(print_row) ~~~
- The
Gameclass has several attributes:-
size: This attribute represents the size of the game grid, indicating the number of rows and columns. -
card_options: This attribute is a list that stores the possible words that can appear on the cards. -
columns: This attribute is a list that stores the column labels for the game grid. -
cards: This attribute is a list that will store theCardobjects for the game. -
locations: This attribute is a list that will store the available locations on the game grid.
-
- The
\_\_init\_\_method is the constructor of theGameclass. It initializes the attributes of the class. In particular:- It sets
sizeto 4, indicating a 4x4 grid. - It defines
card_optionswith a list of eight words. - It sets
columnsas a list of four letters: ‘A’, ‘B’, ‘C’, and ‘D’. - It sets
cardsas an empty list to store theCardobjects. - It generates the list of
locationsby iterating over the columns and row numbers, creating a string representation for each location.
- It sets
- The
set_cardsmethod is responsible for setting up the cards for the game. It goes through each word in thecard_optionslist and randomly assigns two unique locations to each word. It creates aCardobject for each word and location combination, and appends it to thecardslist. - The
create_rowmethod takes a row number as a parameter and generates a list representing the contents of that row on the game grid. It iterates over each column and checks if there is a card at the current location. If there is a matched card, it appends the string representation of the card to the row list. Otherwise, it appends three spaces (‘ ‘) to indicate an empty spot. - The
create_gridmethod generates the entire game grid and prints it to the console. It starts by printing the header row, which consists of the column labels separated by vertical bars. Then, it iterates over each row and calls thecreate_rowmethod to generate the content for that row. It concatenates the row content and prints it.
Finally, at the bottom of the file, there is a section that demonstrates the usage of the Game class:
```python
if __name__ == ‘__main__’:
game = Game()
game.set_cards()
game.cards[0].matched = True
game.cards[1].matched = True
game.cards[2].matched = True
game.cards[3].matched = True
game.create_grid()
~~~
- This section creates an instance of the
Gameclass calledgame. - It
then calls the set_cards method to set up the cards for the game.
- Next, it manually marks the first four cards in the
cardslist as matched by setting theirmatchedattribute toTrue. - Finally, it calls the
create_gridmethod to generate and print the game grid, showing the matched cards and empty spots.
That’s a detailed explanation of the code! The provided code simulates a simple matching card game, where cards are represented by the Card class and the game itself is handled by the Game class.
class card
There is a program written to play random match game, the program contains two files: 1. cards.py; 2. game.py with the following code:
cards.py:
# hold a card
# matched or not?
# location
# \_\_eq\_\_
# \_\_str\_\_
class Card:
def \_\_init\_\_(self, word, location):
self.card = word
self.location = location
self.matched = False
def \_\_eq\_\_(self, other):
return self.card == other.card
def \_\_str\_\_(self):
return self.card
if \_\_name\_\_ == '\_\_main\_\_':
card1 = Card('egg', 'A1')
card2 = Card('egg', 'B1')
card3 = Card('hut', 'D4')
print(card1 == card2)
print(card2 == card3)
print(card1)
game.py:
from cards import Card
import random
class Game:
def \_\_init\_\_(self):
self.size = 4
self.card_options = ['Add', 'Boo', 'Cat', 'Dev', 'Egg', 'Far', 'Gum', 'Hut']
self.columns = ['A', 'B', 'C', 'D']
self.cards = []
self.locations = []
for column in self.columns:
for num in range(1, self.size + 1):
self.locations.append(f'{column}{num}')
def set_cards(self):
used_locations = []
for word in self.card_options:
for i in range(2):
available_locations = set(self.locations) - set(used_locations)
random_location = random.choice(list(available_locations))
used_locations.append(random_location)
card = Card(word, random_location)
self.cards.append(card)
def create_row(self, num):
row = []
for column in self.columns:
for card in self.cards:
if card.location == f'{column}{num}':
if card.matched:
row.append(str(card))
else:
row.append(' ')
return row
def create_grid(self):
header = ' | ' + ' | '.join(self.columns) + ' |'
print(header)
for row in range(1, self.size + 1):
print_row = f'{row}| '
get_row = self.create_row(row)
print_row += ' | '.join(get_row) + ' |'
print(print_row)
def check_match(self, loc1, loc2):
cards = []
for card in self.cards:
if card.location == loc1 or card.location == loc2:
cards.append(card)
if len(cards) == 2:
if cards[0].card == cards[1].card:
cards[0].matched = True
cards[1].matched = True
return True
for card in cards:
print(f'{card.location}: {card}')
return False
def check_win(self):
for card in self.cards:
if not card.matched:
return False
return True
def check_location(self, time):
while True:
guess = input(f"What's the location of your {time} card?")
if guess.upper() in self.locations:
return guess.upper()
else:
print("That's not a valid location. It should look like this: A1")
def start_game(self):
game_running = True
print('Memory Game')
self.set_cards()
while game_running:
self.create_grid()
guess1 = self.check_location('first')
guess2 = self.check_location('second')
if self.check_match(guess1, guess2):
if self.check_win():
print("Congrats! You have guessed them all")
self.create_grid()
game_running = False
else:
input('Those cards are not a match. Press Enter to continue')
print('GAME OVER')
if \_\_name\_\_ == '\_\_main\_\_':
game = Game()
game.start_game()
Explain the code line by line.
Of course! I apologize for the brief explanation earlier. Let’s dive into a more detailed explanation of the code, keeping in mind that you’re a beginner learner.
cards.py:
```python
class Card:
def __init__(self, word, location):
self.card = word
self.location = location
self.matched = False
def \_\_eq\_\_(self, other):
return self.card == other.card
def \_\_str\_\_(self):
return self.card ~~~
- The
cards.pyfile defines a class calledCard. A class is a blueprint for creating objects with certain attributes (variables) and methods (functions) associated with it. - The
Cardclass has three attributes:card,location, andmatched. These attributes store information about the card object, such as its content, position, and whether it has been matched or not. - The
\_\_init\_\_method is a special method called a constructor. It is executed when a new object is created from the class. In this case, it initializes aCardobject with the providedwordandlocationvalues. It also sets thematchedattribute toFalse. - The
\_\_eq\_\_method is another special method that overrides the default equality comparison behavior (==). It allows comparing twoCardobjects based on theircardattributes. If two cards have the samecardvalue, this method will returnTrue, indicating that they are equal. - The
\_\_str\_\_method is also a special method that overrides the default string representation of the object. In this case, it returns thecardattribute as a string.
game.py:
```python
from cards import Card
import random
~~~
- The
game.pyfile imports theCardclass fromcards.pyand therandommodule. Therandommodule is used to generate random choices later in the code.
```python
class Game:
def __init__(self):
self.size = 4
self.card_options = [‘Add’, ‘Boo’, ‘Cat’, ‘Dev’, ‘Egg’, ‘Far’, ‘Gum’, ‘Hut’]
self.columns = [‘A’, ‘B’, ‘C’, ‘D’]
self.cards = []
self.locations = []
for column in self.columns:
for num in range(1, self.size + 1):
self.locations.append(f’{column}{num}’)
~~~
- The
Gameclass is defined to represent the memory matching game. - In the
\_\_init\_\_method, which is the constructor for theGameclass, several attributes are initialized:-
sizeis set to 4, representing the size of the game grid (4x4). -
card_optionsis a list containing the possible words to be placed on the cards. -
columnsis a list representing the columns of the game grid. -
cardsis an empty list that will store theCardobjects. -
locationsis an empty list that will store the possible locations for the cards on the grid.
-
- The nested loops are used to populate the
locationslist with all possible combinations of column and row numbers. For example, it will generate locations like “A1”, “A2”, …, “D4”.
```python
def set_cards(self):
used_locations = []
for word in self.card_options:
for i in range(2):
available_locations = set(self.locations) - set(used_locations)
random_location = random.choice(list(available_locations))
used_locations.append(random_location
)
card = Card(word, random_location)
self.cards.append(card)
~~~
- The
set_cardsmethod is responsible for creating the card objects and assigning them random locations on the grid. - It starts by initializing an empty
used_locationslist to keep track of the card locations that have already been used. - The outer loop iterates over each word in the
card_optionslist. - The inner loop runs twice to create two cards for each word (a total of 16 cards).
- It generates the
available_locationsby subtracting theused_locationsfrom the set of all possible locations. This ensures that the same location is not used for multiple cards. - It selects a random location from the available locations using
random.choice(). - The chosen location is added to the
used_locationslist to prevent its reuse. - A
Cardobject is created with the current word and the chosen location, and it is added to thecardslist.
```python
def create_row(self, num):
row = []
for column in self.columns:
for card in self.cards:
if card.location == f’{column}{num}’:
if card.matched:
row.append(str(card))
else:
row.append(‘ ‘)
return row
~~~
- The
create_rowmethod takes anumparameter representing the row number and returns a list representing the card representations for that row. - It starts by initializing an empty list called
row. - It loops over each column in
self.columns. - For each card in
self.cards, it checks if the card’s location matches the current column and row number. If so, it appends the card’s string representation to the row list (if the card is matched) or appends three spaces to represent a face-down card. - Finally, it returns the
rowlist.
```python
def create_grid(self):
header = ‘ | ‘ + ‘ | ‘.join(self.columns) + ‘ |’
print(header)
for row in range(1, self.size + 1):
print_row = f’{row}| ‘
get_row = self.create_row(row)
print_row += ‘ | ‘.join(get_row) + ‘ |’
print(print_row)
~~~
- The
create_gridmethod is responsible for creating and printing the entire game grid. - It starts by creating the header, which displays the column names separated by ‘|’.
- It then loops over each row number from 1 to
self.size. - For each row, it creates the card representations using the
create_rowmethod and joins them with ‘| ‘. - The resulting row string is printed to display the grid.
```python
def check_match(self, loc1, loc2):
cards = []
for card in self.cards:
if card.location == loc1 or card.location == loc2:
cards.append(card)
if len(cards) == 2:
if cards[0].card == cards[1].card:
cards[0].matched = True
cards[1].matched = True
return True
for card in cards:
print(f’{card.location}: {card}’)
return False
~~~
- The
check_matchmethod is responsible for checking if two selected cards are a match. - It takes two arguments,
loc1andloc2, representing the locations of the selected cards. - It starts by initializing an empty
cardslist. - It loops over each card in
self.cardsand checks if its location matches eitherloc1orloc2. - If a card matches, it
is added to the cards list.
- If the cards list contains exactly two cards, it compares their card attributes to check if they have the same content. If they match, the matched attribute of both cards is set to True, indicating that they have been matched.
- If the cards match, it returns True. Otherwise, it prints the locations and contents of the unmatched cards and returns False.
```python
def check_win(self):
for card in self.cards:
if not card.matched:
return False
return True
~~~
- The
check_winmethod checks if all cards have been matched. - It iterates over each card in
self.cardsand checks if itsmatchedattribute isFalse. If any card is found that is not matched, it returnsFalse, indicating that the game is not yet won. - If all cards have been matched, it returns
True, indicating that the player has won the game.
```python
def check_location(self, time):
while True:
guess = input(f”What’s the location of your {time} card?”)
if guess.upper() in self.locations:
return guess.upper()
else:
print(“That’s not a valid location. It should look like this: A1”)
~~~
- The
check_locationmethod prompts the player to enter the location of a card (either the first or second selection). - It uses a
whileloop to keep prompting until a valid location is entered. - It asks the player for input using
input()and formats the prompt based on thetimeparameter. - It converts the entered location to uppercase using
upper()and checks if it exists in thelocationslist. If it does, the valid location is returned. - If an invalid location is entered, it prints an error message and repeats the prompt.
```python
def start_game(self):
game_running = True
print(‘Memory Game’)
self.set_cards()
while game_running:
self.create_grid()
guess1 = self.check_location(‘first’)
guess2 = self.check_location(‘second’)
if self.check_match(guess1, guess2):
if self.check_win():
print(“Congrats! You have guessed them all”)
self.create_grid()
game_running = False
else:
input(‘Those cards are not a match. Press Enter to continue’)
print(‘GAME OVER’)
if __name__ == ‘__main__’:
game = Game()
game.start_game()
~~~
- The
start_gamemethod is the entry point for running the game. - It sets up the initial game state by calling
set_cards()to create the cards. - It starts a game loop using
while game_runningwheregame_runningis initially set toTrue. - Inside the game loop, it calls
create_grid()to display the current grid to the player. - It prompts the player to enter the locations of two cards using
check_location('first')andcheck_location('second'). - It checks if the selected cards are a match using
check_match(guess1, guess2). If they are, it also checks if the player has won usingcheck_win(). - If the player wins, it displays a congratulatory message, creates the final grid, and exits the game loop by setting
game_runningtoFalse. - If the selected cards don’t match, it prompts the player to continue by pressing Enter.
- Finally, it prints “GAME OVER” when the game is finished.
I hope this more detailed explanation helps you understand the code better. Let me know if you have
any further questions!
Instance attributes can be accessed using a class. Ex: Car.make.
True or False. And explain why?
False.
Instance attributes are specific to an instance of a class, meaning they are accessed using an instance of the class, not the class itself. In the example given, Car.make, it implies accessing the attribute make directly from the Car class. However, instance attributes are associated with individual instances of the class, not the class itself.
To access instance attributes, you need to create an instance of the class first, and then access the attributes using the instance variable. For example, if you have an instance of the Car class called my_car, and it has an attribute make, you would access it using my_car.make.
Here’s an example:
```python
class Car:
def __init__(self, make):
self.make = make
my_car = Car(“Toyota”)
print(my_car.make) # Accessing the instance attribute ‘make’ using the instance ‘my_car’
~~~
In this example, the instance attribute make is accessed using the instance my_car, not the class Car.
1) I want you to create a class called Treehouse.
Challenge:
## Practice OOP Vocabulary Challenge # 2) Add a class attribute called product that is equal to the #### string “coding courses” # 3) Add an initializer method that takes a parameter called name. # 4) Add a name instance attribute set equal to the parameter being passed in. # 5) Create a method called learn. Inside the method return a string that #### contains the name instance attribute so you would get something #### like “Tim is learning to code!” where Tim is the name passed into #### the class. # 6) Create an instance of the class and save it to a variable #### named my_treehouse. Pass in your name as the name parameter. # 7) (And final step) call your learn method and print out the result.
My answer:
class Treehouse:
product = "coding courses"
def \_\_init\_\_(self, name):
self.name = name
def learn(self):
return f'{self.name} is learning to code!'
my_treehouse = Treehouse('Tim')
print(my_treehouse.learn())
When you run the code, it will output “Tim is learning to code!” based on the name you provided during the instance creation.
