Python

Question 1

What is an IDE?

Answer 1

Integrated Development Environment. You can use any text editor to write code. However, most integrated development environments (IDEs) include functionality that goes beyond text editing. They provide a central interface for common developer tools, making the software development process much more efficient. Developers can start programming new applications quickly instead of manually integrating and configuring different software.

Question 2

What are variables and how do you define them?

Answer 2

Variables are containers for storing data values. Separate space between words with underscore(“_”). Structured: variable_name = variable_value. Basically similar to JavaScript, but without variable declaration keywords like var, const, and let.

Question 3

What are some of the data types in Python?

Answer 3

Strings, numbers, boolean, tuples

Question 4

What are strings?

Answer 4

Text encapsulated within quotes(“”). Use \n to start a new line within a quote. Use " to print a quotation mark within a string. You can use string functions (len, index, upper, lower…etc)

Question 5

What is concatnation?

Answer 5

Joining two or more string together.

Question 6

What are some number functions?

Answer 6

str(): convert number to string. Used to concatenate string with numbers.
abs(): convert number to an absolute value.
pow(): pass two parameters, takes the power of the second parameter to the first one.
max(): get the max number from the parameters.
min(): get the min number from the parameters.
round(): round the number

Question 7

How can you import other number functions?

Answer 7

from math import *. Import from the math module.

Question 8

How to get input from user?

Answer 8

using input().
ex: name = input(“Enter your name: “)
age = input(“Enter your age: “)
print(“Hello “ + name + “! You are “ + age)

Question 9

What is the default data type when getting input from user?

Answer 9

string. If you want to work with numbers, you need to convert user input into number. ex: int(), float()

Question 10

What are lists? How do you define them?

Answer 10

a set of data.
ex: friends = [“Kevin”, “Karen”, “Jim”]

Question 11

How do you access the last item on the list?

Answer 11

list[-1]

Question 12

How do you access all of the list items after index 1?

Answer 12

list[1:]

Question 13

How do you access second and third item on the list?

Answer 13

list[1:3]. The last number does not get included on the result

Question 14

What are some of the List Functions?

Answer 14

extend(): allows you to add another list to a list.
append(): allows you to add an item to the end of the list.
insert(): allows you to add in a specific index. takes two parameters (index_number, “add_item”)
remove(): allows you to remove an item from the list
clear(): removes every element from the list
pop(): removes last element from the list
count(): gives you the number of times the element occurred in the list
index(): gives you the index number in the list where the element appears
sort(): sorts the list in ascending order
reverse(): reverse the list items
copy(): copy the list

Question 15

What is a tuple?

Answer 15

similar to lists but wrap elements in () and tuples are immutable. you can make a list of tuples

Question 16

How to create functions? How do you call functions?

Answer 16

def function_name():
function_name()

Question 17

What is if statement?

Answer 17

evaluates a condition. If evaluated True, the code inside the body of it is executed. If not, the code inside the body of if is skipped.

Question 18

what is get in python?

Answer 18

allows you to access values by accessing the key. You can also put in default action if the key is not found.

Question 19

What is a while loop in python? What is the syntax?

Answer 19

allows you to execute a block of code multiple times. until the condition becomes false.
i = 1
while i <= 10:
print(i)
i += 1

print(“Done with loop”)

Question 20

What is a for loop in python? What is the syntax?

Answer 20

used for iterating over a sequence.
for letter in “Giraffe Academy”:
print(letter)

Question 21

What are 2D lists?

Answer 21

lists within a list.

Question 22

How do you write comments? What are they?

Answer 22

start a line with #. For multiple lines, write comment in between ‘'’comment’’’. Does not get recognized when running program. Also to comment out code.

Question 23

What are try and except blocks?

Answer 23

Used for error catching. Allows your program to run smoothly even when errors occurr. Always want to be specific when catching errors.

Question 24

What is the syntax for try and except?

Answer 24

try:
answer = 10/0
number = int(input(“Enter a number: “))
print(number)
except ZeroDivisionError as err:
print(err)
except ValueError:
print(“Invalid Input”)

Question 25

How do you open external files? What are some examples of mode?

Answer 25

open(“file_name”, “mode”).
“a”: append, means append information to end of file
“r+”: read and write
“r”: read

Question 26

What are some rules to keep in mind when reading files?

Answer 26

always want to check if file is readable (use readable function). always want to close file after open (use the close function). Appending you need to be careful because you can mess up the file. If you want to add on a new line, you need to add \n at the beginning. “w” mode overwrites the entire file.

Question 27

What is a module?

Answer 27

Python file that you can import into current python file.

Question 28

How do you install packages in python?

Answer 28

pip install packageName

Question 29

What are classes and objects in python?

Answer 29

Allows you to create your own data types. Class defines what a data type is. Object is the actual data. You can model real world entities and create a data type of it.

Question 30

What are class functions in python?

Answer 30

functions that can be used on the objects of the class

Question 31

What is inheritance in python?

Answer 31

allows you to inherit properties from Class to different Class

Question 32

What is python interpreter?

Answer 32

Environment you can use to run python commands. For example, you can run python commands in the terminal.

Question 33

What are docstrings?

Answer 33

similar to # for commenting out code, but allows you to put in multiple lines. prints when using help()

Question 34

How do you define default values when defining a function?

Answer 34

def greet(who=”Colin”):
print(“Hello,”, who)
who variable can be used

Question 35

What are higher order functions?

Answer 35

functions that operate on other functions

Question 36

What does list[:3] mean?

Answer 36

get the list starting from index 0 and continuing up to but not including index 3.

Question 37

What does list[3:] mean?

Answer 37

get the list starting from index 3 and continuing up to end of list.

Question 38

What does list[1:-1] mean?

Answer 38

get all the list except first and last

Question 39

What does list[-3:] mean?

Answer 39

get the last 3

Question 40

What is list comprehension?

Question 41

What is pandas in python?

Answer 41

data analysis and manipulation tool which includes DataFrames

Question 42

What is iloc and loc in pandas? Whats the difference?

Answer 42

Way to select specific data from a DataFrame. loc is label based and iloc is index based.

Question 43

What is set_index in pandas?

Answer 43

sets the index column to what ever column you want. This is useful if you can come up with an index for the dataset which is better than the current one.

Question 44

What are the coditional selectors in pandas?

Answer 44

isin: lets you select data whose value “is in” a list of values.
ex: reviews.loc[reviews.country.isin([‘Italy’, ‘France’])]

isnull (and it companion notnull): lets you highlight values which are (or are not) empty (NaN).
ex: reviews.loc[reviews.price.notnull()]

Question 45

What are some summary function in DataFrame?

Answer 45

describe(): This method generates a high-level summary of the attributes of the given column.
-> It is type-aware, meaning that its output changes based on the data type of the input.
mean(): shows the mean of the points allotted
unique(): shows list of unique values
counts(): To see a list of unique values and how often they occur in the dataset

Question 46

What is mapping in python pandas? What are the functions?

Answer 46

creating new representations from existing data, or for transforming data from the format it is in now to the format that we want it to be in later.

map(): expect a single value from the Series and return a transformed version of that value.
apply(): the equivalent method if we want to transform a whole DataFrame by calling a custom method on each row.