如何让Virtualenv Wrapper创建的虚拟环境仅包含Python3.0+版本

Hey, I’ve dealt with this exact problem before—let’s get your virtual environments to only use Python 3 and ditch Python 2 entirely:

1. Set Python 3 as the Default for virtualenvwrapper #

First, we need to tell virtualenvwrapper to prioritize Python 3 by default. Open your ~/.bashrc file (or ~/.zshrc if you use Zsh) and add these two lines:

export VIRTUALENVWRAPPER_PYTHON=/usr/bin/python3
export VIRTUALENVWRAPPER_VIRTUALENV=/usr/bin/virtualenv-3

Pro tip: If you’re not sure where your Python 3 or virtualenv-3 are installed, run which python3 and which virtualenv-3 in your terminal to get the correct paths.

After adding these lines, reload your shell configuration to apply the changes:

source ~/.bashrc

2. Force Python 3 for Individual Environments (Optional) #

If you ever need to override the default for a specific environment (or just want to be extra explicit), use the -p flag when creating the environment to point directly to your Python 3 interpreter:

mkvirtualenv -p /usr/bin/python3 your_env_name

This guarantees that only Python 3 is installed in the new environment—Python 2 won’t be included at all.

3. Verify Your Environment is Python 3-Only #

Once your environment is created, activate it and double-check the Python versions to confirm everything worked:

workon your_env_name
python --version  # This should show Python 3.x (e.g., Python 3.8.10)
python2 --version  # This should throw an error like "command not found"—exactly what we want!

Why This Happens in the First Place #

By default, virtualenvwrapper might fall back to your system’s default Python interpreter (which could still be Python 2 on some older setups) if you don’t explicitly configure it to use Python 3. Adding those environment variables to your bashrc ensures it always uses Python 3 unless you intentionally specify otherwise.

内容的提问来源于stack exchange，提问作者Nabin Bogati