Install

Installation is as simple as:

Terminal

pip install 'pydantic<2'

pydantic has no required dependencies except Python 3.7, 3.8, 3.9, 3.10 or 3.11 and typing-extensions. If you’ve got Python 3.7+ and pip installed, you’re good to go.

Pydantic is also available on conda under the conda-forge channel:

Terminal

conda install 'pydantic<2' -c conda-forge

Compiled with Cython

pydantic can optionally be compiled with cython which should give a 30-50% performance improvement.

By default pip install provides optimized binaries via PyPI for Linux, MacOS and 64bit Windows.

If you’re installing manually, install cython<3 (Pydantic 1.x is incompatible with Cython v3 and above) before installing pydantic and compilation should happen automatically.

To test if pydantic is compiled run:

import pydantic
print('compiled:', pydantic.compiled)

Performance vs package size trade-off

Compiled binaries can increase the size of your Python environment. If for some reason you want to reduce the size of your pydantic installation you can avoid installing any binaries using the pip --no-binary option. Make sure Cython is not in your environment, or that you have the SKIP_CYTHON environment variable set to avoid re-compiling pydantic libraries:

Terminal

SKIP_CYTHON=1 pip install --no-binary pydantic pydantic<2

Note

pydantic is repeated here intentionally, --no-binary pydantic tells pip you want no binaries for pydantic, the next pydantic tells pip which package to install.

Alternatively, you can re-compile pydantic with custom build options, this would require having the Cython package installed before re-compiling pydantic with:

Terminal

CFLAGS="-Os -g0 -s" pip install \
  --no-binary pydantic \
  --global-option=build_ext \
  pydantic<2

Optional dependencies

pydantic has two optional dependencies:

• If you require email validation you can add email-validator
• dotenv file support with Settings requires python-dotenv

To install these along with pydantic:

Terminal

pip install 'pydantic[email]<2'
# or
pip install 'pydantic[dotenv]<2'
# or just
pip install 'pydantic[email,dotenv]<2'

Of course, you can also install these requirements manually with pip install email-validator and/or pip install python-dotenv.

Install from repository

And if you prefer to install pydantic directly from the repository:

Terminal

pip install git+https://github.com/pydantic/[email protected]#egg=pydantic
# or with extras
pip install git+https://github.com/pydantic/[email protected]#egg=pydantic[email,dotenv]