Python Environment for Mac

Python environment on Mac

Install pyenv and Python

1. Install pyenv

   curl https://pyenv.run | bash
   

2. Config Environmental Variables
   Add the following to .zshrc

   export PYENV_ROOT="$HOME/.pyenv"
   export PATH="$PYENV_ROOT/bin:$PATH"
   eval "$(pyenv init --path)"
   

3. Reflection of Config ¹

   . ~/.zshrc
   

4. Install Python
   Run the following commands under an administrative directory like your home directory.

   Install required version of python by pyenv command:

   pyenv install 3.11.5
   

   If you need to check what versions can install via pyenv:

   pyenv install --list
   

   You can check installed python version following:

   pyenv versions
   

   If installtion stopped on the way, it may be due to the loaded module.
   Check dependencies by:

   module purge
   

5. Reflact Installed Python
   If set default python version:

   pyenv global 3.8.5
   

   If you want to set the python version only in a specific directory, move to that folder and use the local option.

   pyenv local 3.8.5
   

   You can check these version following commands and local config take precedence over global.

   pyenv global
   pyenv local
   

Usage

1. Create Project-directory
   Create directory named sample1.

   mkdir sample1
   

2. Create Virtual Environment
   Run the following command, in the sample1 directory.

   python3 -m venv .venv
   

   This command creates a virtual environment at the specified directory named .venv.
   You can change the virtual environment name (in the case of this example, this is .venv) is arbitrary.
   If you organize a project by git, add the venv folder to .gitignore.
3. Switch to Virtual Environment
   Run bin/activate in the created virtual environment, .venv.

   . .venv/bin/activate
   

4. Install Packages
   For instance, to install the requests package, use:

   python3 -m pip install requests
   

   You can do this by:

   pip3 install requests
   

5. End Virtual Environment

   deactivate
   

   Check the prompt was changed.

Copy Virtual Environment

A list of packages can be created by following the command.
Here, create a list in a file named requirements.txt.

python3 -m pip freeze > requirements.txt

When you create a new virtual environment or add some new packages, install packages to the virtual environment by the following command at once.

python3 -m pip install -r requirements.txt

When using multiple packages (like for main and develop), create a separated file such as requirements-dev.txt, add

-r requirements.txt

and run

pip3 install -r requirements-dev.txt

This can also install packages in requirements.txt.
So, requirements-dev.txt is follows.

-r requirements.txt
black==23.3.0
flake8==6.0.0

References

• 横田研
• python Japan
• Shun Sakamoto
• Ryo-0131

1. . is equal tosource. ↩