Unit 2 - Lists and Loops

Question 1

.add()

Answer 1

Once a set is created, if we wanted to add an element to a set, we would use the .add() method. If the element already exists, the .add() method will not add the element to the set.

Question 2

.append()

Answer 2

The .append() method allows us to add a new element to the end of a list or other data collection type.

Question 3

.discard()

Answer 3

The .discard() method removes a specified element from the data collection type object. The .discard() method will not raise an error if the element does not exist in the object.

Question 4

.extend()

Answer 4

The .extend() method takes a list (or other data collection type) as an argument and then appends (or adds) all of those elements to the end of another list or data collection.

Question 5

.format() method

Answer 5

With the .format() method, any character value(s) within curly brackets are replaced with the objects that are passed to the .format() method.

Question 6

.insert()

Answer 6

The .insert() method allows us to add an element to a list or other data collection type, in any position.

Question 7

.pop()

Answer 7

The .pop() method modifies the list (or other data collection type) and returns the element that was removed.

Question 8

.remove()

Answer 8

Use the .remove() method if we know the element of a list (or other data collection type) we wish to remove (but not the index); the .remove() method takes away the first instance that the element occurs. If the element does not exist, using this method will raise an error.

Question 9

.sort()

Answer 9

The .sort() method arranges all of the elements in a list (or other data collection type) from the lowest to highest. If the values are strings, the result will be a list of strings in alphabetical order.

Question 10

.strip()

Answer 10

The .strip() method is a string method that removes any spaces before the first character or after the last character.

Question 11

.update()

Answer 11

Use the .update() method to add elements from another iterable object (data collection type) into the current iterable object. If an element exists in both objects, only one element will be updated to the combined data collection type.

Question 12

.values()

Answer 12

The .values() method returns an object that contains the values of the dictionary as a list.

Question 13

2D (Two Dimensions)

Answer 13

A nested list or other data collection type (iterable objects like lists, set, tuple, or dictionary) inside another iterable object is called two dimension or 2D for short. Any data collection type can contain other nested collection types as well in multiple dimensions.

Question 14

Base Case

Answer 14

The base case is where the program no longer calls itself recursively and allows a recursive function to end.

Question 15

Body of the Loop

Answer 15

The body of the loop represents the indented block of code that should be executed repeatedly within the loop during each loop iteration.

Question 16

Data Collection Type

Answer 16

A data collection type is a collection of related values that are organized in a specific way so that they can be used effectively.

Question 17

Debugging by Bisection

Answer 17

Debugging by bisection is the practice of breaking your program code into “sections” for debugging and validation purposes. This will help speed up the debugging process since you may be able to find issues within a section rather than the full program.

Question 18

Definite Iteration

Answer 18

With definite iteration, the number of times the block of code runs should be explicitly defined when the loop actually starts. Typically, this is implemented using the for loop. The for loop has a specific start and endpoint.

Question 19

Dictionary

Answer 19

A dictionary is like a list, but more generalized. Dictionaries store data values in key:value pairs that are changeable, meaning that we can change, add, or remove elements after the dictionary has been created. Dictionaries cannot have two elements of the same key.

Question 20

Element

Answer 20

An element is one of the values in a list (or other data collection type); elements can also be called items.

Question 21

Encapsulation

Answer 21

Encapsulation is an important part of programming where we try to bundle data and functions that belong to a specific topic into a single unit. We do this to restrict direct access to some parts of the function.

Question 22

Flow of Execution

Answer 22

The order in which statements are executed is called the flow of execution. Execution always begins at the first statement of the program. Statements are executed one at a time, in order from top to bottom.

Question 23

Function Definition

Answer 23

A function definition specifies the name of a new function and the sequence of statements that execute when the function is called.

Question 24

Global Scope

Answer 24

Global scope means variables can be accessed throughout the entire program.

Question 25

Indefinite Iteration

Answer 25

A loop that is not specified in advance on how many times to be run; it repeats as long as a condition is met. In Python, indefinite loops are typically created using the while loop.

Question 26

Index

Answer 26

The index (also known as position) is an integer value that indicates an element in a data collection type like a list.

Question 27

Infinite Loop

Answer 27

An infinite loop is a loop in which the terminating condition is never satisfied or for which there is no terminating condition.

Question 28

Iterable

Answer 28

Iterable sounds complex but it is just a fancy name for a Python object that is capable of going through its members one at a time.

Question 29

Iteration

Answer 29

Iteration is the repetition of a process. For programming, that is basically the repetitive execution of code to do something.

Question 30

Iteration Variable

Answer 30

The variable that changes each time the loop executes and controls when the loop finishes.

Question 31

Iterator

Answer 31

Iterator is a type of object that contains a countable number of values. More simply, the iterator is an object that can be used to traverse and move through all its values (elements) within an iterable object.

Question 32

List

Answer 32

The list is the simplest data collection type in Python and it can store multiple values in a single variable.

Question 33

Local Scope

Answer 33

Local scope means that the variables can only be accessed within the block, function, method, or class that they are initialized or used.

Question 34

Mutable

Answer 34

Mutable means that we’re able to change items, add items, or delete items from a data collection type after it has been created.

Question 35

None

Answer 35

The type None is a return type that simply means that there is no data that’s returned.

Question 36

Recursion

Answer 36

With recursion, we have a function call itself with a base case to exit the recursive cycle.

Question 37

Return Statement

Answer 37

The return statement is an important part of functions and methods as it allows the functions and methods to return Python objects back to the code that called them. The return statement is the actual line that starts with the word 'return'.

Question 38

Return Value

Answer 38

These objects that are being returned from the return statement are called the function or method’s return value.

Question 39

Sets

Answer 39

Sets are a data collection type that is used to store multiple elements in a single variable similar to the other data collection types. Set elements are unordered and unchangeable.

Question 40

Tuple

Answer 40

A tuple is a data collection type that is ordered and unchangeable. This means that a tuple uses an indexing structure for its order and its elements can’t be changed after it has been defined.

Question 41

break

Answer 41

This is a reserved keyword that creates a break statement for loops. The break statement can immediately terminate a loop’s execution. When this occurs, the program goes to the first statement/line of code after the loop.

Question 42

continue

Answer 42

This is a reserved keyword that creates a continue statement for loops. The continue statement will end the current loop iteration, meaning that the execution jumps back to the top of the loop. The expression is then evaluated to determine if the loop will execute again or end there.

Question 43

def

Answer 43

The reserved keyword def indicates that you are defining a function.

Question 44

del

Answer 44

del is a reserved keyword and used as the del statement to delete an element. It does not return anything.

Question 45

dict()

Answer 45

The dict() function creates a new dictionary with no elements.

Question 46

divmod()

Answer 46

The divmod() function takes in two numbers as arguments and returns two numbers in a tuple.

Question 47

end

Answer 47

The end parameter is a function of the print() function. Using the end parameter, we are able to change the default operation of the print() function, namely to prevent the print() function from creating a new line.

Question 48

for

Answer 48

In Python, definite iteration loops are generally called for loops. Python’s for loop is a data collection-based iteration (loops through iterable objects such lists, sets, tuples, dictionaries, and even strings).

Question 49

isinstance()

Answer 49

The isinstance() function takes in a variable and the data type as parameters and returns if that variable is of that datatype or not.

Question 50

iter()

Answer 50

The iter() function is used to create an iterator by initializing the object that was passed to it.

Question 51

key:value pair

Answer 51

A key:value pair is used with the dictionary data collection type. Think of a dictionary as a mapping between the index positions (which are called the keys) and a set of values (elements). Each key maps to a value. The association of a key and a value (element) is called a key:value pair.

Question 52

len()

Answer 52

The len function (stands for length) returns the number of elements in a list (or other data collection type).

Question 53

max()

Answer 53

The max function (stands for maximum) returns the largest value in a list (or other data collection type).

Question 54

min()

Answer 54

The min function (stands for minimum) returns the smallest value in a list (or other data collection type).

Question 55

next()

Answer 55

The next() function is used to move to the next value (element) in an iterable object.

Question 56

raise

Answer 56

The raise statement allows the programmer to force a specified exception to occur when it is called.

Question 57

range()

Answer 57

The range() function takes multiple parameters, the starting number (0 by default), and the ending number. This function will increment by 1 (by default) and then stop before a designated number. The function can take an optional third parameter to change the step value (increment or decrement by a specific value other than the default of 1).

Question 58

return

Answer 58

The reserved keyword return is used to exit a function and return a value, either an optional return value we specify or None if no value is specified.

Question 59

slice

Answer 59

The slice operator also works on lists which allows us to return or update specific elements within the list. The slice operator works on any data collection types that are ordered, so this operator will work with lists and tuples.

Question 60

sum()

Answer 60

The sum function returns a number, sum of all values in a list (or other data collection type).

Question 61

while

Answer 61

The while loop is one of the most commonly used loops. It keeps going as long as some condition is true.