pyvenv-3.4

pyvenv-3.4 [options] directory

directory
    The path to the directory where the virtual environment will be created. If the directory does not exist, it will be created.

-h, --help
    Display a help message and exit.

--clear
    Delete the contents of the environment directory if it already exists, then recreate the environment.

--symlinks
    (Default on Unix) Try to use symlinks rather than copying files into the virtual environment.

--copies
    (Default on Windows) Try to use copies rather than symlinks when creating the virtual environment.

--without-pip
    Skip installing pip into the virtual environment. pip is usually installed by default to manage packages.

--system-site-packages
    Give the virtual environment access to the system site-packages directory. By default, environments are isolated from system packages.

pyvenv-3.4 is a command-line utility used to create isolated Python 3.4 environments. It allows users to manage project-specific dependencies without interfering with the system-wide Python installation. When executed, pyvenv-3.4 sets up a new directory containing a copy or symlinks to the Python 3.4 executable, its standard library, and typically an isolated site-packages directory where project-specific packages can be installed.

This specific command is an alias or direct link to the pyvenv utility as shipped with Python version 3.4. It was introduced in Python 3.3 as part of the built-in venv module, aiming to provide a lightweight and official alternative to the popular third-party virtualenv tool. While functional for its intended version, the standalone pyvenv command was deprecated in Python 3.6 in favor of using python -m venv directly. This latter approach is now the standard and recommended way to create virtual environments, as it explicitly ties the environment creation to the invoked Python interpreter.

Deprecation: The pyvenv command (and thus pyvenv-3.4) was deprecated in Python 3.6 and completely removed in Python 3.8. It is strongly recommended to use python3.4 -m venv or simply python -m venv with the appropriate Python version if you need a Python 3.4 environment.

Version Specificity: This command is hard-coded for Python 3.4. It will not work with other Python versions.

Pip Installation: While pip is usually installed by default with venv, older Python 3.4 installations might require the ensurepip module to be run if pip is missing.

To create a new virtual environment named my_env in the current directory using Python 3.4:
pyvenv-3.4 my_env

To activate the newly created environment:
On Linux/macOS:
source my_env/bin/activate
On Windows (Command Prompt):
my_env\Scripts\activate.bat

After activation, commands like python and pip will refer to the versions and installations within my_env, keeping your project's dependencies isolated.

The concept of isolated virtual environments gained significant traction in the Python community with the popular third-party virtualenv tool. Python 3.3 introduced the venv module as a built-in solution, providing pyvenv as its command-line entry point. pyvenv-3.4 would have been the specific executable or link tied to Python 3.4's venv module.

This standalone pyvenv command, however, sometimes caused confusion regarding which Python interpreter it would use if multiple versions were installed. To clarify this and simplify usage, the Python core developers decided to deprecate the standalone pyvenv command in Python 3.6, encouraging users to invoke the venv module directly via python -m venv. This change ensured that the virtual environment was created by the specific python interpreter invoked, removing ambiguity.

python(1), venv(1), virtualenv(1)