Import Statement in Python

Learn how to import modules, functions, classes and variables into a Python program.

What is an Import Statement?

Python provides the import statement to use code from another module.

Instead of writing the same code again, we can create reusable code in a module and import it whenever we need it.

Why Do We Use Import?

• Reuse existing code.
• Avoid duplicate code.
• Use Python's built-in modules.
• Use our own user-defined modules.
• Use functions and classes created in other files.

Import Statement Diagram

The basic idea of importing a module can be understood like this:

1. Importing a Complete Module

The simplest way to import a module is:

import math

print(math.sqrt(25))
print(math.pi)

Output:

5.0
3.141592653589793

Here, math is imported and its functions or variables are accessed using:

module_name.item_name

Example: math.sqrt()

2. Importing a User-Defined Module

Suppose we create a file named calculator.py.

def add(a, b):

    return a + b


def subtract(a, b):

    return a - b

Now create another file: main.py

import calculator

print(calculator.add(10, 20))
print(calculator.subtract(20, 5))

Output:

30
15

We can reuse the functions from calculator.py without writing them again.

3. Using from ... import

We can import only a specific function, class or variable instead of importing the complete module.

from math import sqrt

print(sqrt(36))

Output:

6.0

Now we can use sqrt() directly without writing math.sqrt().

Importing Multiple Items

We can import more than one item from a module.

from math import sqrt, pi

print(sqrt(49))
print(pi)

Output:

7.0
3.141592653589793

Both sqrt and pi are imported from the math module.

4. Using an Alias with as

We can give a shorter name, called an alias, to a module.

import math as m

print(m.sqrt(64))
print(m.pi)

Output:

8.0
3.141592653589793

Here, m is an alias for the math module.

Importing an Item with an Alias

We can also give an alias to a specific imported item.

from math import sqrt as square_root

print(square_root(81))

Output:

9.0

Here, sqrt is imported with the name square_root.

5. Importing Everything

Python also supports importing all public names from a module using the * symbol.

from math import *

print(sqrt(25))
print(pi)

This allows us to use imported names directly.

6. Importing a Class

We can import a class from another module.

Suppose student.py contains:

class Student:

    def __init__(self, name):
        self.name = name

    def display(self):
        print("Name:", self.name)

Now in main.py:

from student import Student

student1 = Student("Rahul")

student1.display()

Output:

Name: Rahul

7. Importing a Variable

Variables can also be imported from another module.

Suppose config.py contains:

company_name = "CIIT Training Institute 🔓🌍...!"

city = "Pune"

Now:

from config import company_name, city

print(company_name)
print(city)

Output:

CIIT Training Institute 🔓🌍...!
Pune

import vs from ... import

Common Modules We Can Import

Common Mistakes

• Writing the wrong module name.
• Forgetting the correct import syntax.
• Importing a function but using the module prefix.
• Creating naming conflicts by importing many names.
• Using import * unnecessarily.

Example 🤓👀

Suppose we create a module named calculator.py:

def add(a, b):

    return a + b


def multiply(a, b):

    return a * b

Then in main.py:

from calculator import add, multiply

result1 = add(10, 20)

result2 = multiply(5, 4)

print("Addition:", result1)
print("Multiplication:", result2)

Output:

Addition: 30
Multiplication: 20