Creating custom modules in Python - Practice Exercises

Challenge - 5 Problems

❓ Predict Output

intermediate

Output of importing and using a custom module function

Consider you have a file named mymath.py with this content:

def add(a, b):
    return a + b

What will be the output of this code?

import mymath
print(mymath.add(3, 4))

Python

import mymath
print(mymath.add(3, 4))

A 7

B 34

C TypeError

D NameError

💡 Hint

Remember that the function add returns the sum of two numbers.

The function add in mymath module adds two numbers. Calling mymath.add(3, 4) returns 7, which is printed.

❓ Predict Output

intermediate

Output when importing a module with a syntax error

Given a file mymodule.py with this content:

def greet(name):
    print(f"Hello, {name}!")

if True
    print("This line has a syntax error")

What happens when you run this code?

import mymodule
mymodule.greet("Alice")

Python

import mymodule
mymodule.greet("Alice")

A Hello, Alice!

B SyntaxError

C NameError

D IndentationError

💡 Hint

Check the if statement syntax in the module.

The module has a missing colon after 'if True', causing a SyntaxError when imported.

🔧 Debug

advanced

Why does this custom module import fail?

You have a file calculator.py with:

def multiply(x, y):
    return x * y

And this code in another file:

from Calculator import multiply
print(multiply(2, 3))

What is the cause of the error when running this code?

Python

from Calculator import multiply
print(multiply(2, 3))

A NameError because multiply is not defined

B TypeError because multiply is not a function

C SyntaxError because import statement is wrong

D ModuleNotFoundError because module name is case-sensitive

💡 Hint

Python module names are case-sensitive and must match the file name exactly.

The file is named 'calculator.py' but the import uses 'Calculator' with uppercase C. This causes ModuleNotFoundError.

📝 Syntax

advanced

Which import statement correctly imports all functions from a custom module?

You have a module tools.py with several functions.
Which option correctly imports all functions so you can call them directly without prefix?

A import tools.*

B from tools import all

C from tools import *

D import * from tools

💡 Hint

The syntax for importing all names from a module uses 'from module import *'.

Option C uses correct Python syntax to import all functions from tools so they can be called directly.

🚀 Application

expert

What is the output of this custom module usage with __name__ check?

Given a file greetings.py with:

def say_hello():
    print("Hello from greetings")

if __name__ == "__main__":
    say_hello()

And this code in another file:

import greetings
print("Imported greetings module")

What will be printed when running the second file?

Python

import greetings
print("Imported greetings module")

A Imported greetings module

B

Hello from greetings
Imported greetings module

C No output

D NameError

💡 Hint

Code inside 'if __name__ == "__main__"' runs only when the module is executed directly.

When greetings.py is imported, __name__ is 'greetings', so the say_hello() inside the if block does not run. Only the print in the second file runs.