virtualenv

library21.2.0pypypiunverified

virtualenv is a tool for creating isolated Python environments, allowing developers to manage dependencies for different projects separately. The current version is 21.2.0, with regular updates to enhance functionality and maintain compatibility with Python versions.

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pip install virtualenv

github ↗package ↗homepage ↗docs ↗

INSTALL

IMPORT

SIG · VIRTUALENV

virtualenv

devopspythonv21.2.0

harness data pending

Install & Compatibility

Where this runs

No compatibility data collected yet for this library.

Code

Verified usage

This script demonstrates how to create, activate, use, and deactivate a virtual environment using virtualenv.

import os # Create a virtual environment os.system('virtualenv myenv') # Activate the virtual environment if os.name == 'nt': os.system('.\\myenv\\Scripts\\activate') else: os.system('source myenv/bin/activate') # Install a package within the virtual environment os.system('pip install requests') # Deactivate the virtual environment os.system('deactivate')

virtualenv --version

Debug

Known issues

breakingvirtualenv 21.0.0 refactored the discovery module, which may affect custom scripts relying on internal APIs.

fix

Review and update custom scripts to align with the new discovery module structure.

affects: 21.0.0 and later

deprecatedThe --relocatable option is experimental and may not work in all circumstances.

fix

Avoid using the --relocatable option; consider other methods for creating portable environments.

affects: All versions

gotchaCreating a virtual environment without specifying the Python version may result in using an unintended interpreter.

fix

Use the -p option to specify the desired Python interpreter when creating a virtual environment.

affects: All versions

gotchaSystem-wide PYTHONPATH settings can interfere with virtualenv's isolation.

fix

Ensure PYTHONPATH is unset or correctly configured when working within a virtual environment.

affects: All versions

gotchaMoving a virtual environment directory can break its functionality due to absolute paths.

fix

Recreate the virtual environment in the new location instead of moving it.

affects: All versions

gotchaActivation or deactivation of the virtual environment fails with 'sh: 1: source: not found' or 'sh: 1: deactivate: not found' errors, indicating that the shell's `source` command is not available or the activation script cannot be found in the current shell environment (e.g., when using a minimal shell like dash without sourcing capabilities).

fix

Ensure that the shell executing the activation command supports `source` (e.g., Bash, Zsh). If a minimal shell is used, consider explicitly calling the Python interpreter from the virtual environment's `bin` directory (e.g., `/path/to/venv/bin/python`) or ensure the `PATH` is correctly updated manually, or switch to a compatible shell for activation.

affects: All versions

gotchaThe 'deactivate' command was not found or could not be executed by the shell. This can occur if the virtual environment's activation script was not properly sourced, or if the 'deactivate' script is missing or corrupted.

fix

Ensure the virtual environment is correctly activated using 'source /path/to/venv/bin/activate'. If the issue persists, verify the integrity of the 'deactivate' script within the virtual environment's 'bin' directory or recreate the virtual environment.

affects: All versions

Errors

Common errors & fixes

virtualenv: command not found

The `virtualenv` command is not installed, or its executable location is not included in your system's PATH environment variable.

fix

Install virtualenv globally using pip: `pip install virtualenv`.

failed to create virtual environment

The virtual environment could not be created because the target directory does not exist or the user lacks write permissions for that location.

fix

Ensure the parent directory exists and you have write permissions, or specify a different path: `mkdir my_project && cd my_project && virtualenv venv`.

Cannot find python interpreter

`virtualenv` could not automatically locate a Python executable at common system paths.

fix

Specify the full path to your desired Python interpreter using the `-p` flag: `virtualenv -p /usr/bin/python3.9 my_env`.

'activate' is not recognized as an internal or external command, operable program or batch file.

On Windows, the virtual environment activation script needs to be run by specifying its full path and correct file extension, typically from the `Scripts` directory.

fix

In Command Prompt, use: `.\my_env\Scripts\activate.bat`. In PowerShell, use: `.\my_env\Scripts\Activate.ps1`.

Upgrade

Version history

21.2.0latest on PyPI · released Mar 9, 2026

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Dependencies

No dependency data recorded yet.

Agent activity

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Resources

githubhttps://github.com/pypa/virtualenv ↗

packagehttps://pypi.org/project/virtualenv/ ↗

homepagehttps://virtualenv.pypa.io ↗

docshttps://virtualenv.pypa.io ↗