On Virtual Environment of Python

Different meanings of "virtuality"

I had been confused with several different packages for realizing "virtual environments" of Python, before finding the following clear article.

https://medium.freecodecamp.org/manage-multiple-python-versions-and-virtual-environments-venv-pyenv-pyvenv-a29fb00c296f

In short,

• "venv" can create multiple different environments on a single python version, so that one can have different sets of packages installed for each environment.
• "pyenv" makes it possible for a machine to have different python versions(>=3.3) installed.

So, if one wants to have different environments with various python versions, you need "venv" and "pyenv"; Note that "venv" is included in main python bundle.

venv usages

To create a new virtual environment with "venv" just run python with options and parameters as "-m venv new_environement_path".

I found someone advocating a nice practice to name the new environment's path simply "venv" and to have it under the project directory which uses the environment.

https://qiita.com/fiftystorm36/items/b2fd47cf32c7694adc2e

To activate a virtual environment

$ source path_to_your_virtual_environement/bin/activate

To deactivate

$ deactivate

• To see which python versions are available online(not on the local machine)
  pyenv install --list
• To install python version 9.9.9
  peen install 9.9.9
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