ModuleNotFoundError: No module named 'yaml' in Python

ModuleNotFoundError: No module named 'yaml' in Python #

The Python "ModuleNotFoundError: No module named 'yaml'" occurs when we forget to install the pyyaml module before importing it or install it in an incorrect environment. To solve the error, install the module by running the pip install pyyaml command.

Open your terminal in your project's root directory and install the pyyaml module.

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# 👇️ in a virtual environment or using Python 2
pip install pyyaml

# 👇️ for python 3 (could also be pip3.10 depending on your version)
pip3 install pyyaml

# 👇️ if you get permissions error
sudo pip3 install pyyaml
pip install pyyaml --user

# 👇️ if you don't have pip in your PATH environment variable
python -m pip install pyyaml

# 👇️ for python 3 (could also be pip3.10 depending on your version)
python3 -m pip install pyyaml

# 👇️ using py alias (Windows)
py -m pip install pyyaml

# 👇️ for Anaconda
conda install -c conda-forge pyyaml

# 👇️ for Jupyter Notebook
!pip install pyyaml

After you install the pyyaml package, try importing it as follows.

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import yaml

print(yaml.load("""
 - Hesperiidae
 - Papilionidae
 - Apatelodidae
 - Epiplemidae
 """, Loader=yaml.Loader)
      )

The Python error "ModuleNotFoundError: No module named 'yaml'" occurs for multiple reasons:

1. Not having the pyyaml package installed by running pip install pyyaml.
2. Installing the package in a different Python version than the one you're using.
3. Installing the package globally and not in your virtual environment.
4. Your IDE running an incorrect version of Python.
5. Naming your module yaml.py which would shadow the official module.
6. Declaring a variable named yaml 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.

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python --version

For example, my Python version is 3.10.4, so I would install the pyyaml package with pip3.10 install pyyaml.

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pip3.10 install pyyaml

# 👇️ if you get permissions error use pip3 (NOT pip3.X)
sudo pip3 install pyyaml

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:

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# 👇️ make sure to use your version of Python, e.g. 3.10
python3 -m pip install pyyaml

If the "No module named 'yaml'" error persists, try restarting your IDE and development server/script.

You can check if you have the pyyaml package installed by running the pip show pyyaml command.

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# 👇️ check if you have pyyaml installed
pip3 show pyyaml

# 👇️ if you don't have pip set up in PATH
python3 -m pip show pyyaml

The pip show pyyaml 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.

For example, In VSCode, you can press CTRL + Shift + P or (⌘ + 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 dropdown menu.

If you are using a virtual environment, make sure you are installing pyyaml in your virtual environment and not globally.

You can try creating a virtual environment if you don't already have one.

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# 👇️ use correct version of Python when creating VENV
python3 -m venv venv

# 👇️ activate on Unix or MacOS
source venv/bin/activate

# 👇️ activate on Windows (cmd.exe)
venv\Scripts\activate.bat

# 👇️ activate on Windows (PowerShell)
venv\Scripts\Activate.ps1

# 👇️ install pyyaml in virtual environment
pip install pyyaml

If the python3 -m venv venv command doesn't work, try the following 2 commands:

• python -m venv venv
• py -m venv venv

Your virtual environment will use the version of Python that was used to create it.

You also shouldn't be declaring a variable named yaml as that would also shadow the original module.

If the error is not resolved, try to uninstall the pyyaml package and then install it.

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# 👇️ check if you have pyyaml installed
pip3 show pyyaml

# 👇️ if you don't have pip set up in PATH
python3 -m pip show pyyaml

# 👇️ uninstall pyyaml
pip3 uninstall pyyaml

# 👇️ if you don't have pip set up in PATH
python3 -m pip uninstall pyyaml

# 👇️ install pyyaml
pip3 install pyyaml

# 👇️ if you don't have pip set up in PATH
python3 -m pip install pyyaml

Try restarting your IDE and development server/script.

You can also try to upgrade the version of the pyyaml package.

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pip3 install pyyaml --upgrade

# 👇️ if you don't have pip set up in PATH
python3 -m pip install pyyaml --upgrade

This one is for using virtual environments (VENV) on Windows:

This one is for using virtual environments (VENV) on MacOS and Linux:

Conclusion #

The Python "ModuleNotFoundError: No module named 'yaml'" occurs when we forget to install the pyyaml module before importing it or install it in an incorrect environment. To solve the error, install the module by running the pip install pyyaml command.