Master Python Virtual Environments with virtualenv and PyCharm on Windows

1. Installing virtualenv

virtualenv can be installed like any other Python package, either via pip or from source.

1.1 Install with pip

pip install virtualenv

To uninstall, run pip uninstall virtualenv. If pip is not available, use the source method below.

1.2 Install from source

Download the latest tar.gz from the official site, extract it, then run: c:\virtualenv-15.1.0>python setup.py install If pip is missing, install the latest pip tar.gz first.

2. Configuring a Python virtual environment

Use virtualenv to create an isolated environment for a specific project directory and Python version. For example, to set up a Python 3.6 environment for c:\PythonProj\sjtu-cs: virtualenv -p c:\Python36\python.exe HigEnv The -p flag specifies the Python executable; HigEnv is the name of the new environment.

3. Activating the virtual environment

c:\PythonProj\sjtu-cs>cd HigEnv\Scripts
c:\PythonProj\sjtu-cs\HigEnv\Scripts>activate

After activation, you can run Python commands, e.g.: >>> python "hello ,world" To deactivate, simply run:

(HigEnv) c:\PythonProj\sjtu-cs\HigEnv\Scripts>deactivate

4. Using virtualenv in PyCharm

PyCharm integrates virtualenv, so you often do not need to install it manually.

4.1 Create a new project and select the Python version

When importing an existing project, PyCharm auto‑detects the matching interpreter, but you can also choose a different one.

4.2 Create a virtualenv interpreter in PyCharm

In the project settings, add a new interpreter and let PyCharm create a virtualenv for you, or point it to an existing environment.

Alternatively, you can skip creating a new environment and directly select the desired interpreter for the project.