Borislav Hadzhiev
Wed Apr 20 2022ยท4 min read
Photo by Raychan
The Python "ModuleNotFoundError: No module named 'Crypto'" occurs when we
forget to install the pycryptodome
module before importing it or install it in
an incorrect environment. To solve the error, install the module by running the
pip install pycryptodome
command.
Open your terminal in your project's root directory and install the
pycryptodome
module.
# ๐๏ธ in a virtual environment or using Python 2 pip install pycryptodome # ๐๏ธ for python 3 (could also be pip3.10 depending on your version) pip3 install pycryptodome # ๐๏ธ if you get permissions error sudo pip3 install pycryptodome # ๐๏ธ if you don't have pip in your PATH environment variable python -m pip install pycryptodome # ๐๏ธ for python 3 (could also be pip3.10 depending on your version) python3 -m pip install pycryptodome # ๐๏ธ for Anaconda conda install -c conda-forge pycryptodome
After you install the pycryptodome package, try importing it like:
from Crypto.Cipher import AES from Crypto.Random import get_random_bytes data = b'secret data' key = get_random_bytes(16) cipher = AES.new(key, AES.MODE_EAX) ciphertext, tag = cipher.encrypt_and_digest(data) file_out = open("encrypted.bin", "wb") [file_out.write(x) for x in (cipher.nonce, tag, ciphertext)] file_out.close()
The Python error "ModuleNotFoundError: No module named 'Crypto'" occurs for multiple reasons:
pycryptodome
package installed by running
pip install pycryptodome
.crypto.py
which would shadow the official module.Crypto
which would shadow the imported variable.If the error persists, get your Python version and make sure you are installing the package using the correct Python version.
python --version
For example, my Python version is 3.10.4
, so I would install the pycryptodome
package with pip3.10 install pycryptodome
.
pip3.10 install pycryptodome # ๐๏ธ if you get permissions error use pip3 (NOT pip3.X) sudo pip3 install pycryptodome
Notice that the version number corresponds to the version of pip
I'm using.
If the PATH for pip
is not set up on your machine, replace pip
with
python3 -m pip
:
# ๐๏ธ make sure to use your version of Python, e.g. 3.10 python3 -m pip install pycryptodome
If the "No module named 'Crypto'" error persists, try restarting your IDE and development server / script.
You can check if you have the pycryptodome
package installed by running the
pip show pycryptodome
command.
# ๐๏ธ check if you have pycryptodome installed pip3 show pycryptodome # ๐๏ธ if you don't have pip setup in PATH python3 -m pip show pycryptodome
The pip show pycryptodome
command will either state that the package is not
installed or show a bunch of information about the package, including the
location where the package is installed.
If the package is not installed, make sure your IDE is using the correct version of Python.
pycryptodome
package using the incorrect version or your IDE might be setup to use a different version.For example, In VSCode, you can press CTRL + Shift + P
or (โ
+ Shift
+ P
on Mac) to open the command palette.
Then type "Python select interpreter" in the field.
Then select the correct python version from the drop down menu.
If you are using a virtual environment, make sure you are installing
pycryptodome
in your virtual environment and not globally.
You can try creating a virtual environment if you don't already have one.
# ๐๏ธ use correct version of Python when creating VENV python3 -m venv venv # ๐๏ธ activate on Unix or MacOS source venv/bin/activate # ๐๏ธ activate on Windows (cmd.exe) venv\Scripts\activate.bat # ๐๏ธ activate on Windows (PowerShell) venv\Scripts\Activate.ps1 # ๐๏ธ install pycryptodome in virtual environment pip install pycryptodome
Your virtual environment will use the version of Python that was used to create it.
crypto.py
because that would shadow the original pycryptodome
module.You also shouldn't be declaring a variable named Crypto
as that would also
shadow the original module.
If the error is not resolved, try to uninstall the pycryptodome
package and
then install it.
# ๐๏ธ check if you have pycryptodome installed pip3 show pycryptodome # ๐๏ธ if you don't have pip setup in PATH python3 -m pip show pycryptodome # ๐๏ธ uninstall pycryptodome pip3 uninstall pycryptodome # ๐๏ธ if you don't have pip setup in PATH python3 -m pip uninstall pycryptodome # ๐๏ธ install pycryptodome pip3 install pycryptodome # ๐๏ธ if you don't have pip setup in PATH python3 -m pip install pycryptodome
Try restarting your IDE and development server / script.
You can also try to upgrade the version of the pycryptodome package.
pip3 install pycryptodome --upgrade # ๐๏ธ if you don't have pip setup in PATH python3 -m pip install pycryptodome --upgrade
This one is for using using virtual environments (VENV) on Windows
:
This one is for using using virtual environments (VENV) on MacOS
and Linux
: