Practice: Variables and Data Types¶

View practice code on GitHub Get the Video Course

Seven practice problems, one per concept step. The numbers line up (Practice-01 goes with Step-01). Read the task, write the program yourself, then check python-practice/solutions. Some problems are short input() "Write a Program" exercises.

Step-01: Your First Program¶

Concepts: print().

Write a program that prints a small "About Me" card for Kalyan, who is learning Python. It has three lines: a title, the name, and what is being learned.

About Me
Name: Kalyan
Learning: Python

print("About Me")
print("Name: Kalyan")
print("Learning: Python")

Pages for this step: Concept | Practice | Workshop

Python Files for this step: Concept | Practice | Practice Solutions | Workshop | Workshop Solutions

Step-02: Comments¶

Concepts: comments (file comment, inline comment, commented-out line, triple-quote block).

Write a program that prints Hello and, along the way, uses each kind of comment: a file comment at the top, an inline comment on the Hello line, a commented-out line, and a triple-quote block that hides three lines (Line1, Line2, Line3) without using #. Only Hello should appear in the output.

Hello

# Hello program
print("Hello")  # this is the hello program
# print("Goodbye")
"""
Line1
Line2
Line3
"""

Pages for this step: Concept | Practice | Workshop

Python Files for this step: Concept | Practice | Practice Solutions | Workshop | Workshop Solutions

Step-03: print() Options and Escape Sequences¶

Concepts: print() with sep and end, and the escapes \n and \t.

Problem-1

Write a program that prints red, green, blue on one line, separated by ,.

red, green, blue

# Problem-1 Task-1: print three colors separated by comma
print("red", "green", "blue", sep=", ")

Problem-2

Write a program that prints Loading and done on the same line, joined by ... (no line break between them).

Loading...done

# Problem-2 Task-1: join two words with ... on one line
print("Loading", end="...")
print("done")

Problem-3

Write a program that prints a two-line table from a single string: Name: then Kalyan, and City: then Hyderabad, with the values lined up by a tab.

Name:   Kalyan
City:   Hyderabad

# Problem-3 Task-1: print a tab-aligned two-line table
print("Name:\tKalyan\nCity:\tHyderabad")

Problem-4

Write a program that prints the Windows path C:\Temp\data on one line and She said "Hi" on the next. You will need to escape the backslashes and the quotes.

C:\Temp\data
She said "Hi"

# Problem-4 Task-1: print escaped path and quoted text
print("C:\\Temp\\data")
print("She said \"Hi\"")

Pages for this step: Concept | Practice | Workshop

Python Files for this step: Concept | Practice | Practice Solutions | Workshop | Workshop Solutions

Step-04: Variables¶

Concepts: variables, changing a variable's value, print() with several values and sep, naming rules and conventions.

Problem-1

Write a program that stores a name (Kalyan) and a city (Hyderabad) in variables, then prints an intro card: the title Intro Card, the labeled name and city, a blank line, and finally the name and city on one line joined by -.

Intro Card
Name: Kalyan
City: Hyderabad

Kalyan - Hyderabad

# Problem-1 Task-1: store name and city, print intro card
name = "Kalyan"
city = "Hyderabad"

print("Intro Card")
print("Name:", name)
print("City:", city)

print()
print(name, city, sep=" - ")

Problem-2

Write a program that stores a course title and lesson count in snake_case variables (course_title = Python for Beginners, lesson_count = 50) and a maximum rating as an UPPER_CASE constant (MAX_RATING = 5), then prints all three.

Python for Beginners
50
5

# Problem-2 Task-1: snake_case vars and UPPER_CASE constant, print all three
course_title = "Python for Beginners"
lesson_count = 50
MAX_RATING = 5

print(course_title)
print(lesson_count)
print(MAX_RATING)

Problem-3

Write a program that stores an age of 30 and prints it, then changes age to 31 after a birthday and prints it again.

30
31

# Problem-3 Task-1: store an age, change it after a birthday, print both
age = 30
print(age)
age = 31
print(age)

Pages for this step: Concept | Practice | Workshop

Python Files for this step: Concept | Practice | Practice Solutions | Workshop | Workshop Solutions

Step-05: Data Types and type()¶

Concepts: the four data types (str, int, float, bool), type(x).__name__.

Problem-1

Write a program that stores a book's title (Python Crash Notes), pages (96), price (14.99), and in_stock (True), one value of each core type. Print all four values, then print each value's type name (in the same order).

Python Crash Notes
96
14.99
True
str
int
float
bool

# Problem-1 Task-1: store four core-type values, print values then type names
title = "Python Crash Notes"
pages = 96
price = 14.99
in_stock = True

print(title)
print(pages)
print(price)
print(in_stock)

print(type(title).__name__)
print(type(pages).__name__)
print(type(price).__name__)
print(type(in_stock).__name__)

Problem-2

Write a program that stores amount = 12.3456 and:

• Task-1: print it rounded to 2 decimal places.
• Task-2: print it rounded to 1 decimal place.
• Task-3: print it rounded to a whole number (no decimals).

12.35
12.3
12

amount = 12.3456
# Problem-2 Task-1: print rounded to 2 decimals
print(round(amount, 2))
# Problem-2 Task-2: print rounded to 1 decimal
print(round(amount, 1))
# Problem-2 Task-3: print rounded to a whole number
print(round(amount))

Pages for this step: Concept | Practice | Workshop

Python Files for this step: Concept | Practice | Practice Solutions | Workshop | Workshop Solutions

Step-06: Type Conversion¶

Concepts: int(), float(), str(), input().

Problem-1

Write a program that makes three conversions:

• Task-1: turn the text 15 into a whole number, add 10, and print the result.
• Task-2: turn the text 3.5 into a decimal number and print it.
• Task-3: build the text age 30 by joining age with the number 30 and print it.

25
3.5
age 30

# Problem-1 Task-1: convert text to int, add 10, print
quantity = int("15")
print(quantity + 10)
# Problem-1 Task-2: convert text to float and print
print(float("3.5"))
# Problem-1 Task-3: join text with a number and print
print("age " + str(30))

Problem-2 (Write a Program)

Write a program that asks the user for two numbers and prints their sum. (Remember: what the user types comes in as text, so convert it before adding.)

Enter the first number: 10
Enter the second number: 20
30

# Problem-2 Task-1: read two numbers and print their sum
a = int(input("Enter the first number: "))
b = int(input("Enter the second number: "))
print(a + b)

Problem-3 (Write a Program)

Write a program that asks for a name and an age, then greets the user and tells them how old they will be next year, for example Hi Kalyan, next year you will be 31.

Enter your name: Kalyan
Enter your age: 30
Hi Kalyan, next year you will be 31

# Problem-3 Task-1: read name and age, greet with next-year age
name = input("Enter your name: ")
age = int(input("Enter your age: "))
print("Hi " + name + ", next year you will be " + str(age + 1))

Pages for this step: Concept | Practice | Workshop

Python Files for this step: Concept | Practice | Practice Solutions | Workshop | Workshop Solutions

Step-07: Keywords¶

Concepts: the keyword module.

Write a program that prints how many hard keywords Python has, then checks and prints whether if, class, and course are Python keywords. Print each line in the form shown below.

Total hard keywords: 35
Is 'if' a keyword? True
Is 'class' a keyword? True
Is 'course' a keyword? False

import keyword

print("Total hard keywords:", len(keyword.kwlist))
print("Is 'if' a keyword?", keyword.iskeyword("if"))
print("Is 'class' a keyword?", keyword.iskeyword("class"))
print("Is 'course' a keyword?", keyword.iskeyword("course"))

Pages for this step: Concept | Practice | Workshop

Python Files for this step: Concept | Practice | Practice Solutions | Workshop | Workshop Solutions

Next: Practice: Strings and fstrings