Python Basics

Question 1

Variable Names
What do computers use variables for?

Answer 1

To remember informaion

Question 2

Variable Names
To create a variable, we start by typing it name. Variable names need to be single words and therefore have no spaces.

Answer 2

city

Question 3

Variable Names
If we want a variable name with multiple words, we use snake case. Snake case means using _ to connect the additional words.

Answer 3

home_city

Question 4

Variable Names
What’s wrong with this variable name?
high score

Answer 4

There is a space between the words.

Question 5

Variable Names
To help us understand what’s inside a variable we pick descriptive names.

Answer 5

home_city_province

Question 6

Variable Names
What do we use snake case for?

Answer 6

To create variable names with multiple words.

Question 7

Updating Variables
Why do we give variables descriptive names like city or population instead of c or p?

Answer 7

To help us understand what’s inside them.

Question 8

Expressions
We can add string values together with a + sign

Answer 8

“Followers:” + “55”

Question 9

Expressions
We call adding string values and expression as the output creates a single value.
In this example, only oh string is displayed output when we add “55” inside print().

Answer 9

print(“Followers:” + “55”)
Followers:55

Question 10

Expressions
When expressions contain variables, they use the values in the variables, which we can see when adding “Followers:” to followers.

Answer 10

followers = “55”
print (“Followers:”+followers)

Question 11

Expressions
Since expressions become values, we can store them in variables the same way as values.
See the example her where we’ll code label to display the expression.

Answer 11

label = “Posts:” + “13”
print(label)
Posts:13

Question 12

Expressions
What’s the value of label?
label = “Name:” + “Joe”

Answer 12

“Name:Joe”

Question 13

Expressions
What does the code display in the console?
user = “snoopdogg”
print(“Username:” + user)

Answer 13

Username:snoopdogg

Question 14

Expressions
Add temperature variable to the expression.
temperature = “14”
print(temperature + “ degrees”

Answer 14

14 degrees

Question 15

Expressions
Display Posts:55 in the console

Answer 15

Print (“Posts:” + “55”)
Posts:55

Question 16

Expressions
Display Ms. Irene in the console
title = “Ms. “
name = “Irene”

Answer 16

print(title + name)
Ms. Irene

Question 17

Expressions
Code the string value “likes” so that the code displays 40 likes.

Answer 17

number_of_likes = “40 “
print(number_of_likes + “likes”)
40 likes

Question 18

Numbers
We’ve seen before that variables can also store numbers. Unlike strings, numeric values don’t use quotes “”

Answer 18

active_users = 5

Question 19

Numbers
We can create expressions with numbers, too. Here, we can add numbers together with + 1

Answer 19

number_of_applications = 5 + 1
print(number_of_applications)
6

Question 20

Numbers
We use the * sign to multiply numbers and the / sign to divide numbers. We’ll turn 0.5 into its percent value by multiplying it by 100.

Answer 20

percent = 0.5 * 100
print(percent)
50.0

Question 21

Numbers
We can use variables with numbers for calculations, too. We’ll see it in action by adding 1 to number_of_steps.

Answer 21

number_of_steps = 70
print(“You’re on step:”)
print(number_of_steps + 1)
You’re on step:
71

Question 22

Numbers
Since expressions become values, we can store calculation results in variables, like her where total contains private + public.

Answer 22

private = 3
public = 10
total = private + public
print(“Total posts:”)
print(total)
Total posts:
13

Question 23

Numbers
What’s the value of speed?
speed = 300 + 5

Answer 23

305

Question 24

Numbers
Why does this code display 31 instead of 4 in the console?
temperature = “3” + “1”
print(temperature)

Answer 24

31
Because “3” and “1” are string values

Question 25

Numbers
How do we know that the score variable stores a number?
score = 40 + 4

Answer 25

Because there are no double quotes around 40 and 4

Question 26

Numbers
What does the code display in the console?
area = “3 * 5”
print (area)

Answer 26

3 * 5

Question 27

Numbers
Multiply the savings variable by the interest variable.

Answer 27

savings = 100
interest = 0.04
print (savings * interest)
4.0

Question 28

Numbers
Divide sum_of_grades by students to get the average grade of a class.

Answer 28

sum_of_grades = 460
students = 5
print(sum_of_grades / students)
92.0

Question 29

Numbers
Subtract discount from total and display the calculation result in the console.

Answer 29

total = 100
discount = 20
print(“Discounted price:”
print(total - discount)
Discount price:
80

Question 30

Set months_per_year to 12

Answer 30

months_per_year = 12
print(months_per_year)
12