A Module in python is a file containing definitions and statements. A module can define functions, classes and variables. Modules help organize code into separate files so that programs become easier to maintain and reuse. Instead of writing everything in one place, related functionality can be grouped into its own module and imported whenever needed.
Create a Python Module
To create a Python module, write the desired code and save that in a file with .py extension. Let's understand it better with an example:
Example: Let's create a calc.py in which we define two functions, one add and another subtract.
Python
# calc.py
def add(x, y):
return (x+y)
def subtract(x, y):
return (x-y)
This is all that is required to create a module.
Import module
Modules can be used in another Python file using the import statement. When Python sees an import, it loads the module if it exists in the interpreter’s search path.
Syntax:
import module
Example: Now, we are importing the calc that we created earlier to perform add operation.
Python
import calc
print(calc.add(10, 2))
Output
12
Explanation: import calc loads the module and calc.add() accesses a function through dot notation.
Types of Import Statements
1. Import From Module: This allows importing specific functions, classes, or variables rather than the whole module.
Python
from math import sqrt, factorial
print(sqrt(16))
print(factorial(6))
Explanation: Only sqrt and factorial are brought into the local namespace, so the prefix math. is not required.
2. Import All Names: * imports everything from a module into the current namespace.
Python
from math import *
print(sqrt(16))
print(factorial(6))
Explanation: Every public name of math becomes directly accessible. (Not recommended in large projects due to namespace conflicts.)
3. Import With Alias: You can shorten a module’s name using as.
Python
import math as m
print(m.pi)
Explanation: math is accessed through the shorter alias m.
Types of Modules in Python
Python provides several kinds of modules. Each type plays a different role in application development.
1. Built-in Modules: These come bundled with Python and require no installation - e.g., math, random, os.
Python
import random
print(random.randint(1, 5))
Explanation: random.randint() returns a random number within the given range.
2. User-Defined Modules: These are modules you create yourself, such as calc.py.
Python
import calc
print(calc.sub(20, 5))
Output
15
Explanation: The module is created manually and then imported into another script.
3. External (Third-Party) Modules: These modules are installed using pip - e.g., NumPy, Pandas, Requests.
Python
import requests
r = requests.get("https://example.com")
print(r.status_code)
Output
200
Explanation: requests is installed separately (pip install requests) and provides HTTP utilities.
4. Package Modules: A package is a directory containing multiple modules, usually with an __init__.py file.
Example Directory
mypkg/
__init__.py
calc.py
utils.py
Using a module from a package
Python
from mypkg import utils
print(utils.some_func())
calls a function named some_func(), the output will be whatever that function returns.
If utils.py contains something like:
Python
def some_func():
return "Hello"
Output
Hello
Locating a Module
Python searches for modules in a predefined list of directories known as the module search path. You can view this list using sys.path.
Python
import sys
for p in sys.path:
print(p)
Output/home/guest/sandbox
/usr/local/lib/python313.zip
/usr/local/lib/python3.13
/usr/local/lib/python3.13/lib-dynload
/usr/local/lib/python3.13/site-packages
Explanation: Python checks each path in order until it finds the module you’re trying to import.
Also Read:
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Python Fundamentals
Python Data Structures
Advanced Python
Data Science with Python
Web Development with Python
Python Practice