Environment Setup
- Operating System: Windows 10
- Python Version: 3.6.7
virtualenv
Installation
virtualenv creates isolated Python environments, allowing different project dependencies to remain separate. Install it using pip on Windows:
pip install virtualenv
Creating a Virtual Environment
Use the virtualenv command with appropriate parameters to create a new environment:
virtualenv --no-site-packages -p C:\Python36\python.exe myenv
Parameters explained:
--no-site-packages: Prevents access to global site-packages-p: Specifies the Python interpreter to usemyenv: Directory name for the new environment
Activating and Deactivating
Navigate to the Scripts directory within your virtual environment and run the activate script:
F:\myenv>cd Scripts
F:\myenv\Scripts>activate
(myenv) F:\myenv\Scripts>
Note: Use Command Prompt (cmd.exe) instead of PowerShell. The activate script does not properly update the prompt indicator in PowerShell.
To deactivate the virtual environment:
(myenv) F:\myenv\Scripts>deactivate
F:\myenv\Scripts>
Command Options
Basic Usage
virtualenv [OPTIONS] DEST_DIR
Available Options
| Option | Description |
|---|---|
--version |
Display installed version |
-h, --help |
Show help message |
-v, --verbose |
Increase output verbosity |
-q, --quiet |
Reduce output verbosity |
-p PYTHON_EXE, --python=PYTHON_EXE |
Specify Python interpreter path |
--clear |
Clear non-root enstallations and rebuild |
--no-site-packages |
Block access to global site-packages |
--system-site-packages |
Allow access to global site-packages |
--unzip-setuptools |
Extract Setuptools or Distribute during install |
--relocatable |
Make existing environment relocatable |
--distribute |
Use Distribute instead of Setuptools |
--extra-search-dir=SEARCH_DIRS |
Search directories for packages |
--never-download |
Prevent downloading from network |
--prompt=PROMPT |
Set custom prompt prefix |
virtualenvwrapper
virtualenvwrapper provides convenience wrappers around virtualenv, simplifying workflow. Ensure virtualenv is installed first.
Linux Installation
pip install virtualenvwrapper
Add the following to ~/.bashrc:
export WORKON_HOME=~/.virtualenvs
export VIRTUALENVWRAPPER_PYTHON=/usr/local/bin/python3
source /usr/local/bin/virtualenvwrapper.sh
Apply changes:
source ~/.bashrc
Windows Installation
pip install virtualenvwrapper-win
After installation, configure the environment variable:
- Open System Properties
- Navigate to Advanced System Settings
- Click Environment Variables
- Under System Variables, create a new variable:
- Variable name:
WORKON_HOME - Variable value: Absolute path for storing virtual environments
- Variable name:
Common commands with virtualenvwrapper on Windows:
workon # List available environments
workon myenv # Activate specific environment
deactivate # Deactivate current environment
rmvenv myenv # Remove an environment