What is modulenotfounderror: no module named ‘crypto’ in Python?
The error “modulenotfounderror: no module named ‘crypto'” occurs in Python when you forget to install the “pycryptodome” module before importing it or installing it in the wrong environment.
Why does this error occur?
The no module named ‘crypto’ in Python error message occurs because of the following reasons:
- The module is not installed.
- The module is installed in a different Python environment.
- Python interpreter cannot find the ‘crypto’ module in your environment.
- Your Integrated Development Environment (IDE) is using an incorrect Python version
- You’re installing the module in a different version of Python than the one you’re actually using.
What is a ‘crypto’ module in Python?
The “crypto” module in Python, is a component of the PyCrypto library.
This module encompasses a variety of secure hash functions, including SHA256 and RIPEMD160, along with several encryption algorithms such as AES, DES, RSA, ElGamal, and others.
Unfortunately, PyCrypto is not actively maintained anymore and it is being deprecated.
On the other hand, it is advised to use the “pycryptodome” module as an alternative.
How to fix the modulenotfounderror: no module named ‘crypto’ in Python?
To fix this error, you need to install the “pycryptodome” module.
If you have “crypto” or “pycrypto” modules installed, it’s suggested to uninstall them first to avoid collisions.
Solution 1: Install the pycryptodome
Here are the commands you can use:
Use the following command if you are using Python 2:
pip install pycryptodomeUse the following command if you are using Python 3:
pip3 install pycryptodomeUse the following command if you get a permissions error:
sudo pip3 install pycryptodomeor
pip install pycryptodome --userUse the following command if you are using Anaconda:
conda install -c conda-forge pycryptodomeUse the following command if you are using Jupyter Notebook:
!pip install pycryptodomeIf you don’t have pip in your PATH environment variable, you can use the following command:
python -m pip install pycryptodomeFor python 3:
python3 -m pip install pycryptodomeSolution 2: Check if the module is installed
To check if the module is installed, use the following command:
pip show pycryptodomeSolution 3: Check the spelling
Please ensure the spelling of your module is correct, as there may be instances where it has been misspelled.
Solution 4: Check the version of Python
To check the version of Python you are currently using, use the following command:
Python -VSolution 5: Reinstalling the module
If the error still exists, try to reinstall the module.
Use the following command to uninstall:
pip uninstall pycryptodome
Use the following command to install pycryptodome:
pip install pycryptodomeConclusion
In conclusion, the error “ModuleNotFoundError: No module named ‘Crypto'” error message pops up when your Python environment lacks the “pycryptodome” module.
To fix this error, the command pip install pycryptodome needs to be executed.
By following the guide above, there’s no doubt that you’ll be able to resolve this error quickly.
We hope that you’ve resolved the error with the help of this guide. Thank you for reading, and have fun coding!
Frequently Asked Questions
What is Python ModuleNotFoundError and what causes it?
ModuleNotFoundError (a subclass of ImportError) is raised when Python cannot find the module you tried to import. Common causes: the package isn’t installed (pip install missing), wrong virtual environment activated, typo in module name, or Python can’t find your local module on the import path. The error message names exactly which module is missing.
How do I fix ‘ModuleNotFoundError: No module named X’?
Run pip install X first. If that succeeds but you still get the error, check which Python you’re using (which python OR python –version) vs which pip (which pip OR pip –version), they must match. Common gotcha: pip points to system Python 3.9 but you’re running python3.11 in a venv. Inside the venv, use python -m pip install X to be sure pip matches the active Python.
Why does my code work in one environment but not another?
Different Python versions or different installed packages. To diagnose: pip freeze > requirements.txt on the working environment, then pip install -r requirements.txt on the broken one. Use virtualenv (python -m venv venv) or conda for every project to avoid system-wide package collisions.
Is ModuleNotFoundError the same as ImportError?
ModuleNotFoundError is a subclass of ImportError added in Python 3.6. It specifically means ‘no such module exists.’ Plain ImportError covers a wider set: module exists but a name inside it can’t be imported (e.g. ‘cannot import name X from Y’). except ImportError catches both; except ModuleNotFoundError catches only the missing-module case.
Where can I find more ModuleNotFoundError fixes?
Browse the ModuleNotFoundError reference hub for 198+ specific module fixes (TensorFlow, Flask, Django, pandas, numpy, etc.). For related issues see ImportError. For broader Python setup see Python Tutorial hub.
Caren Bautista
Technical Writer at PIES IT Solution
Responsible for crafting clear, well-structured, and beginner-friendly content across the platform. Handles the writing, proofreading, and editorial review of tutorials, guides, and documentation to ensure every article is accurate, readable, and easy to follow.
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