In this guide, you'll set up a local Python development environment with multiple Python versions, managed by pyenv.
This guide differs from the Google Cloud Python development instructions because developers of samples and libraries need to be able to use multiple versions of Python to test their code.
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Install homebrew if you do not already have it.
Note: If you are running Catalina (MacOS 10.15.x), ensure that you have a compatible version of Homebrew (2.1.13 or later). Running
brew update
on Catalina does not always result in a compatible version, so uninstall and reinstall homebrew, if necessary
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Install pyenv.
brew update brew install pyenv
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Install the pyenv-virtualenv plugin.
brew install pyenv-virtualenv
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Append the following to your
~/.bashrc
:eval "$(pyenv init -)" eval "$(pyenv virtualenv-init -)"
Note: This also works with ZSH.
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Reload your shell.
source ~/.bashrc
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See the available Python versions with pyenv.
pyenv install --list
Note: The Python versions are at the top of the long list. If the Python version you want isn't listed, you may need to upgrade your pyenv with homebrew.
brew update brew upgrade pyenv
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Install the necessary Python versions with pyenv. Use the latest release of the versions you wish to test against. A list of available versions is available on python.org
As of April 28, 2022, the latest Python versions are:
- 3.6.13 (latest 3.6.x release)
$ pyenv install 3.6.13
- 3.7.13 (latest 3.7.x release)
$ pyenv install 3.7.13
- 3.8.13 (latest 3.8.x release)
$ pyenv install 3.8.13
- 3.9.12 (latest 3.9.x release)
$ pyenv install 3.9.12
- 3.10.4 (latest 3.10.x release)
$ pyenv install 3.10.4
ℹ️ Note: If you are using an M1 Mac, certain versions of Python will not properly install with pyenv due to incompatibilities with
clang
. Python 3.6.13, 3.7.13, and 3.8.13 will work, but earlier patches Python 3.6, Python 3.7, and Python 3.8 may not.ℹ️ Note: If you are getting errors installing a python version, try setting up the
SDKROOT
environment variable.# You can add this to your .bashrc file. export SDKROOT=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX.sdk
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After you have installed a python version through pyenv, verify that you are now using the pyenv Python shim.
$ which python ~/.pyenv/shims/python
Pyenv allows you to configure the priority order for your python installs.
pyenv global 3.8.5 3.7.8 3.6.11 3.5.9 2.7.18
This will make python and python3 point to Python 3.8.5. python2 will use 2.7.18. You can also further specify versions, such as python3.6 to use that version.
Using Virtual Environments
prevents inadvertent modifications to your global python install. Once
created and sourced, calls to python
will use this virtual environment, not
a global python install. Each virtual environment can have its own set of
packages that can be different from others.
Python has builtin support for creating virtual environments, accessible by
running the venv
module.
cd python-docs-samples
python -m venv [venv-name]
source [venv-name]/bin/activate
Typically you will name the venv venv
, or venv38
for a python 3.8 venv.
You can also use an extension for pyenv that will assist in managing virtual
environments. This allows you to use pyenv local
to automatically use the
created virtual environment. You can install this by running
$ brew install pyenv-virtualenv
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Change to the desired source directory.
cd ~/src/python-docs-samples
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Create a virtualenv for python 3.8.5 using
pyenv virtualenv
.pyenv virtualenv 3.8.5 python-docs-samples
This creates a virtualenv folder within
~/.pyenv/versions/
. -
Set the local Python version(s) with
pyenv local
# pyenv local [name of virtualenv] [list of python versions to use] pyenv local python-docs-samples 3.8.5 3.7.8 3.6.11 3.5.9 2.7.18
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Now, when you
cd
into the source directory or a subdirectory within it, pyenv will make your virtualenv the default Python. Since you specified more than one version, it will also add binaries likepython36
andpython27
to your PATH, which nox uses when picking Python interpreters. -
Add
.python-version
to your global gitignore file, so it won't be committed into the repository.
If you are looking for more information on how to author samples, please view the Authoring Guide