Python Virtual Environment Setup

TIL_20230216_Python_VirtualEnvironment.md

Python Virtual Environment

Best practice before creating python project to avoid dependencies error across programs is to code in virtual environment.

Setup

Go to desired directory in the terminal, then type in command line:

Windows:

python -m venv virtualEnvironmentName

p/s: Shorter name is better like venv or virt. For example:

python -m venv venv

Mac:

python3 -m venv virtualEnvironmentName

A directory of virtualEnvironmentName/ should be made in the selected path.

Activate the virtualEnvironmentName via the terminal:

source virtualEnvironmentName/Scripts/activate

Now, the (virtualEnvironmentName) should be shown in the Terminal above the directory:

Once the venv activated, continue working like normal in local machine.

Deactivate the virtualEnvironmentName via the terminal:

deactivate

The output will be: Notice the (virtualEnvironmentName) is deactivated and not shown after the deactive command.

Install libraries

Show Installed Libraries

pip freeze

For a newly setup venv, nothing should be returned as it just freshly built.

After installing via pip install <libraryName>, the output should be e.g.:

Creation of requirements.txt

At the end of the project, do this:

• Windows:

pip freeze > requirements.txt

• Mac/Linux:

pip3 freeze > requirements.txt

So that, other user can simple recreate the venv via:

• Windows:

pip install -r requirements.txt

• Max/Linux:

pip install -r requirements.txt