ModuleNotFoundError: No module named

Fix 'ModuleNotFoundError: No module named' errors in Python. Learn to install missing packages, fix import paths, and manage virtual environments.

What Does This Error Mean?

The 'ModuleNotFoundError: No module named' error occurs when Python's import system cannot find the module you are trying to import. The module is either not installed, not in the Python path, or the import statement has a typo or incorrect structure.

Common Causes

The package is not installed in the current environment

You are running code in the wrong virtual environment or no environment

The module name is misspelled in the import statement

The file is in a subpackage but the import path is missing the parent package

The package was installed for a different Python version (e.g., Python 2 vs 3)

Circular imports causing the module to be unavailable at import time

How to Fix It

Install the missing package with pip

Use pip to install the package in your current environment.

# Install the missing package
pip install package-name

# For Python 3 specifically
pip3 install package-name

# Install from requirements file
pip install -r requirements.txt

# Check installed packages
pip list
pip show package-name

Activate the correct virtual environment

Ensure you are using the virtual environment where the package is installed.

# Windows
venv\Scripts\activate

# macOS / Linux
source venv/bin/activate

# Check which Python is being used
which python
# Windows: where python

# Verify packages in the active environment
pip list

Fix PYTHONPATH for local modules

Add the parent directory to PYTHONPATH when importing local modules.

import sys
import os

# Add the project root to the path
sys.path.append(os.path.dirname(os.path.dirname(__file__)))

# Or set it before running
# $env:PYTHONPATH = "C:\path\to\project"  # PowerShell
# export PYTHONPATH="/path/to/project"        # bash

Check for circular imports

Restructure your code to avoid two modules importing each other.

# ❌ Circular import
# module_a.py: from module_b import func_b
# module_b.py: from module_a import func_a

# ✅ Solution: move shared code to a third module
# shared.py: shared constants and types
# module_a.py: from shared import ...
# module_b.py: from shared import ...

# ✅ Or use lazy imports inside functions
def run_task():
  from module_b import func_b  # Import only when needed
  func_b()

Before & After Examples

❌ Before

import requests
# ModuleNotFoundError: No module named requests

✅ After

# Install first
$ pip install requests
# Then import works
import requests
response = requests.get("https://api.example.com")

Related Tools

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Related Errors

Other common errors in this category:

IndentationError: unexpected indent

Fix 'IndentationError: unexpected indent' in Python. Learn Python's indentation rules and how to fix spacing issues.

KeyError

Fix Python KeyError when accessing dictionary keys that do not exist. Learn to use .get(), setdefault(), and try-except safely.

ImportError: cannot import name

Fix 'ImportError: cannot import name' in Python. Learn why imports fail within modules and how to restructure your code to avoid circular dependencies.

AttributeError: 'NoneType' object has no attribute

Fix AttributeError: 'NoneType' object has no attribute errors in Python. Learn why functions return None and how to handle missing return values.

Frequently Asked Questions

What is the difference between ModuleNotFoundError and ImportError?

ModuleNotFoundError is a subclass of ImportError. ModuleNotFoundError means the module itself was not found. ImportError is broader — it can also mean a specific name was not found within a module (e.g., `from x import y` where y does not exist in x).

Why does pip install work but Python still cannot find the module?

This usually means pip installed the package for a different Python version than the one running your script. Check with `pip --version` and `python --version` to ensure they match. Use `python -m pip install package-name` to guarantee the correct Python is targeted.

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