Setting Up Virtual Environments for Multiple Python Versions

Setting Up Virtual Environments for Multiple Python Versions

In some cases, you may need to work on multiple projects with different Python versions. To avoid conflicts and ensure that each project uses the correct version of Python, you can set up virtual environments for each project. Virtual environments are isolated Python environments that allow you to install packages and dependencies specific to a project, without affecting the global Python installation.

Creating Virtual Environments

To create a virtual environment for a project using venv, navigate to the project directory in your terminal and run the following command:

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python2 -m venv env

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python3 -m venv env

You can replace env with any name you prefer.

Activating Virtual Environments

To start using a virtual environment, you need to activate it. Activating a virtual environment sets the correct Python version and environment variables for the current shell session.

To activate a virtual environment, run the following command:

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source env/bin/activate

Once you have activated a virtual environment, you can install packages and dependencies specific to your project using pip. Any packages you install will only be available within the virtual environment.

Deactivating Virtual Environments

When you finish working in the virtual environment and want to return to the system’s default settings, use:

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deactivate

This command will revert all changes made to the environment by activation.

Managing Dependencies with requirements.txt

To manage dependencies within a virtual environment:

• Creating a requirements.txt: Save all current dependencies to a file:

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pip freeze > requirements.txt

• Installing from requirements.txt:

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pip install -r requirements.txt

This ensures that you can replicate your environment exactly on another machine or in another environment.

Cheers! 🍺