Python

Question 1

#

Answer 1

Python interprets anything after a # as a comment

Question 2

print( “ “ )

Answer 2

Function used to print whatever is put in the quotes

Question 3

Strings

Answer 3

Blocks of text, can be within “ “ or ‘ ‘

Question 4

Variables

Answer 4

We can store data for reuse, variables are assigned by using =

Variables cannot have spaces or symbols in their names, only underscore can be used as a space

Question 5

Two common errors in python

Answer 5

SyntaxError

NameError

Question 6

SyntaxError

Answer 6

Means there is something wrong with the way your program is written - punctuation, command in wrong spot, missing parenthesis

Question 7

NameError

Answer 7

Occurs when the Python interpreter sees a word it does not recognize

Code that contains something that looks like a variable but was never defined

Question 8

Integer

Answer 8

Data type that is a whole number

int

Question 9

Floating point number

Answer 9

A data type that is a decimal number

float

Question 10

Literal

Answer 10

A number that is actually a number and not a variable

print(variable + 3)

Question 11

Changing numbers

Answer 11

Variables will not be changed when performing arithmetic

Variables will only update with =

Question 12

Modulo

Answer 12

% operator

Gives the remainder of a division calculation

If the two numbers are divisible then the result will be 0

This is good in programming for use if we want to perform an action every nth time

Question 13

Concatenation

Answer 13

The + operator can be used to combine variables that are strings together

If we want to combine a number and string together and store it as a variable then we need to convert the number variable to a string using str()

If we just want to print the variables we do not need to convert the number variable to a string. We can simply use commas in the print operator - print( , , )

Question 14

+=

Answer 14

Shorthand operator to add to the current value of a variable

Question 15

“ “ “

Answer 15

Allows spacing of strings to multiple lines or including quote marks within your strings

Question 16

Functions

Answer 16

Allow to group code into reusable blocks. It is a sequence of steps that can be performed repeatedly without having to rewrite the code

Question 17

Defining a function

Answer 17

def function_name( parameter1, parameter2, parameter3, etc ):
print( … )
print( … )

Remove the indent of the line to end the function

Question 18

Parameter vs argument

Answer 18

A parameter is defined with the function and is treated as a variable

The argument is the data that is passed into the function in the form of that variable when the function is called using the argument

Question 19

Types of arguments

Answer 19

Positional arguments

Keyword arguments

Default arguments

Question 20

Positional argument

Answer 20

Standard way of definition. The order in which you enter your arguments will be assigned according to the order in which the parameters were defined

Question 21

Keyword argument

Answer 21

When entering your argument, you bypass the positional definition of the parameters and simply call out the definition directly in the function call

def function(x, y, z)

function(y=5, z=3, x=1)

Question 22

Default argument

Answer 22

When defining the function we can assign a default value to the parameter

When calling the function we can enter no argument at that position to keep the default or enter a value to replace the default

def function(x, y=10)

function(x)

Question 23

Variable scope

Answer 23

If a variable is defined outside of a function then it can be used anytime

If it is only defined within a function then it can only be used when calling the function

Question 24

Returns

Answer 24

def calculation(x, y)
return x * y

Functions can return a value to the program so that it can be modified or used later

Question 25

Returned function value

Answer 25

A result from a function that is stored in a variable

Question 26

Boolean expression

Answer 26

A statement that can either be true or false It will be returned as True and not “True”. I.e. a Boolean value and not a string It is a bool data type Variables with a bool type are Boolean variables

Question 27

Relational operators / comparators

Answer 27

Operators that compare two items and return either true or false Equals == Not equals != String != integer > >= < <=

Question 28

Conditional statement syntax

Answer 28

if is_raining: print(“bring an umbrella”) The : represents the Then part of the if and what comes after the colon will be executed if it is true

Question 29

Boolean operators

Answer 29

And - all conditions must be met in order to be True Or - only one condition must be met in order to be True Not - reverses a Boolean value not True == False if not x > 5: print(“ “)

Question 30

Else statements

Answer 30

Else statements allow us to elegantly describe what we want our code to do when conditions are not met rather than using not Else statements always appear with if if weekday: print(“wake up at 6:30”) else: print(“sleep in”)

Question 31

Else if statements

Answer 31

elif Allow us to check multiple ifs Will check in the order it is written

Question 32

List

Answer 32

Allows us to work with a collection of data in sequential order Heights = [61, 70, 67, 64] Lists can contain any data type together It is not required for a list to have values list = []

Question 33

List methods

Answer 33

Append - adds a single element to the end of the list - example_list.append(5) Remove - remove an element from the list - example_list.append(5) Add multiple - updated list = list1 + [“ex1”, “ex2”]

Question 34

List index

Answer 34

Lists are indexed and the starting index is 0 print(list[0]) We can select the last element of the list using -1 even if we don’t know the length of the list

Question 35

Replacing a value in a list

Answer 35

We can directly replace a value in a list by calling the index List[5] = ‘strawberries’

Question 36

Zip()

Answer 36

Used to combine two lists new_list = zip(list1, list2) In order to print the list you need to use the list() function print_new_list = list(new_list)

Question 37

.count()

Answer 37

A list method to count the number of occurrences of an element in a list

Question 38

.insert()

Answer 38

A list method to insert an element into a specific index of a list

Question 39

.pop()

Answer 39

A list method to remove an element from a specific index or from the end of a list

Question 40

range()

Answer 40

A built in python function to create a sequence of integers my_range = range(2, 9, 2) Creates a range starting at 2 up to 8 counting by 2s

Question 41

len()

Answer 41

A built in python function to get the length of a list

Question 42

.sort() / sorted()

Answer 42

A method and a built in function to sort a list .sort will modify the existing list sorted() will create a new list

Question 43

Slicing

Answer 43

sliced_list = list[first index : index+1 of the last item we want to include] Slice section from beginning up to n list[:n] Slice section from end up to n list[-n:] Slice section but leave remainder n list[:-n]

Question 44

Indefinite iteration

Answer 44

The number of times the loop is executed depends on how many times a condition is met

Question 45

Definite iteration

Answer 45

The number of times the loop will be executed is defined in advance

Question 46

for loop

Answer 46

A definite iteration for in :

Question 47

Using range() with for loop

Answer 47

Allows to define a certain number of iterations without caring what is in the list for temp in range(6): print(“Learning Loops!”)

Question 48

while loop

Answer 48

An indefinite iteration Will perform a set of instructions as long as a condition is true while :

Question 49

Loop break

Answer 49

We can break a loop when a condition is met for item in items_on_sale: print(item) if item == “knit dress”: break

Question 50

continue

Answer 50

Used in loop to skip for i in big_number_list: if i <= 0: continue print(i) this will skip negative numbers and only print positive numbers in the number list

Question 51

List comprehensions

Answer 51

We can write loops in a cleaner way in python numbers = [ … , … , ] doubled = [num*2 for num in numbers] print(doubled) We can also add if, in this case to only double negative numbers numbers = [ … , … , ] negative_doubled = [num*2 for num in numbers if num < 0] print(negative_doubled)