[Solved] Python for Everybody - Chapter 2: Variables, Expressions, and Statements

This tutorial gives you the solutions to the exercises in Chapter 2 of the book Python for Everybody: Exploring Data Using Python 3 by Charles R. Severance.

Link to the book:

• PDF
• Amazon

Solutions for other chapters:

• [Solved] Python for Everybody - Chapter 2: Variables, Expressions, and Statements (this tutorial)
• [Solved] Python for Everybody - Chapter 3: Conditional Execution
• [Solved] Python for Everybody - Chapter 5: Iteration
• [Solved] Python for Everybody - Chapter 6: Strings
• [Solved] Python for Everybody - Chapter 8: Lists

Contents

• 1. Chapter 2: Variables, Expressions, and Statements - Exercise 2
• 2. Chapter 2: Variables, Expressions, and Statements - Exercise 3
• 3. Chapter 2: Variables, Expressions, and Statements - Exercise 4
• 4. Chapter 2: Variables, Expressions, and Statements - Exercise 5

1. Chapter 2: Variables, Expressions, and Statements - Exercise 2

Exercise 2: Write a program that uses input to prompt a user for their name and then welcomes them.

Answer:

name = input('Enter your name: ')
print('Hello', name)

Output:

python exercise-2.py
Enter your name: Minh Vu
Hello Minh Vu

Explanation:

1. We use the input function to prompt the user for their name by displaying the message Enter your name:.
2. The input function returns the user's input as a string then we assign it to the variable name.
3. We use the print function to display the message Hello followed by the user's name.

2. Chapter 2: Variables, Expressions, and Statements - Exercise 3

Exercise 3: Write a program to prompt the user for hours and rate per hour to compute gross pay.

Answer:

hours = float(input('Enter Hours: '))
rate = float(input('Enter Rate: '))
pay = hours * rate
 
print('Pay:', pay)

Output:

python exercise-3.py
Enter Hours: 35
Enter Rate: 2.75
Pay: 96.25

Explanation:

1. Similar to exercise 2, we use the input function to prompt the user for the number of hours and the rate per hour.
2. However, as the input function returns the user's input as a string, we need to convert it to a float using the float function.
3. We then calculate the gross pay by multiplying the number of hours and the rate per hour.
4. Finally, we use the print function to display the gross pay.

Advanced:

We can use the round function to round the gross pay to 2 decimal places.

hours = float(input('Enter Hours: '))
rate = float(input('Enter Rate: '))
pay = hours * rate
 
print('Pay:', pay)
print('Pay:', round(pay, 2))

3. Chapter 2: Variables, Expressions, and Statements - Exercise 4

Exercise 4: Assume that we execute the following assignment statements:

width = 17
height = 12.0

For each of the following expressions, write the value of the expression and the type (of the value of the expression).

1. width//2
2. width/2.0
3. height/3
4. 1 + 2 * 5

Use the Python interpreter to check your answers.

Answer:

width = 17
height = 12.0
 
print(width//2, type(width//2))
print(width/2.0, type(width/2.0))
print(height/3, type(height/3))
print(1 + 2 * 5, type(1 + 2 * 5))

Output:

python exercise-4.py
8 <class 'int'>
8.5 <class 'float'>
4.0 <class 'float'>
11 <class 'int'>

Explanation:

1. width//2 is an integer division, so the result is an integer.
2. width/2.0 is a float division, so the result is a float.
3. height/3 is a float division, so the result is a float.
4. 1 + 2 * 5 is a mathematical expression, so the result is an integer.

4. Chapter 2: Variables, Expressions, and Statements - Exercise 5

Exercise 5: Write a program that prompts the user for a Celsius temperature, convert the temperature to Fahrenheit, and print out the converted temperature.

Answer:

celsius = float(input('Enter Celsius temperature: '))
fahrenheit = celsius * 9 / 5 + 32
 
print('Fahrenheit temperature:', fahrenheit)

Output:

python exercise-5.py
Enter Celsius temperature: 99
Fahrenheit temperature: 210.2

Explanation:

1. The formula to convert Celsius to Fahrenheit is F = C * 9 / 5 + 32.
2. We use the input function to prompt the user for the Celsius temperature.
3. We then convert the Celsius temperature to Fahrenheit using the formula above.
4. Finally, we use the print function to display the Fahrenheit temperature.