Creation of :ref:`virtual environments <venv-def>` is done by executing thecommand ``venv``::python3 -m venv /path/to/new/virtual/environmentRunning this command creates the target directory (creating any parentdirectories that don't exist already) and places a ``pyvenv.cfg`` file in itwith a ``home`` key pointing to the Python installation from which the commandwas run (a common name for the target directory is ``.venv``). It also createsa ``bin`` (or ``Scripts`` on Windows) subdirectory containing a copy/symlinkof the Python binary/binaries (as appropriate for the platform or argumentsused at environment creation time). It also creates an (initially empty)``lib/pythonX.Y/site-packages`` subdirectory (on Windows, this is``Lib\site-packages``). If an existing directory is specified, it will bere-used... deprecated:: 3.6``pyvenv`` was the recommended tool for creating virtual environments forPython 3.3 and 3.4, and is `deprecated in Python 3.6<https://docs.python.org/dev/whatsnew/3.6.html#deprecated-features>`_... versionchanged:: 3.5The use of ``venv`` is now recommended for creating virtual environments... highlight:: noneOn Windows, invoke the ``venv`` command as follows::c:\>c:\Python35\python -m venv c:\path\to\myenvAlternatively, if you configured the ``PATH`` and ``PATHEXT`` variables foryour :ref:`Python installation <using-on-windows>`::c:\>python -m venv c:\path\to\myenvThe command, if run with ``-h``, will show the available options::usage: venv [-h] [--system-site-packages] [--symlinks | --copies] [--clear][--upgrade] [--without-pip] [--prompt PROMPT]ENV_DIR [ENV_DIR ...]Creates virtual Python environments in one or more target directories.positional arguments:ENV_DIR A directory to create the environment in.optional arguments:-h, --help show this help message and exit--system-site-packagesGive the virtual environment access to the systemsite-packages dir.--symlinks Try to use symlinks rather than copies, when symlinksare not the default for the platform.--copies Try to use copies rather than symlinks, even whensymlinks are the default for the platform.--clear Delete the contents of the environment directory if italready exists, before environment creation.--upgrade Upgrade the environment directory to use this versionof Python, assuming Python has been upgraded in-place.--without-pip Skips installing or upgrading pip in the virtualenvironment (pip is bootstrapped by default)--prompt PROMPT Provides an alternative prompt prefix for thisenvironment.Once an environment has been created, you may wish to activate it, e.g. bysourcing an activate script in its bin directory... versionchanged:: 3.4Installs pip by default, added the ``--without-pip`` and ``--copies``options.. versionchanged:: 3.4In earlier versions, if the target directory already existed, an error wasraised, unless the ``--clear`` or ``--upgrade`` option was provided... note::While symlinks are supported on Windows, they are not recommended. Ofparticular note is that double-clicking ``python.exe`` in File Explorerwill resolve the symlink eagerly and ignore the virtual environment.The created ``pyvenv.cfg`` file also includes the``include-system-site-packages`` key, set to ``true`` if ``venv`` isrun with the ``--system-site-packages`` option, ``false`` otherwise.Unless the ``--without-pip`` option is given, :mod:`ensurepip` will beinvoked to bootstrap ``pip`` into the virtual environment.Multiple paths can be given to ``venv``, in which case an identical virtualenvironment will be created, according to the given options, at each providedpath.Once a virtual environment has been created, it can be "activated" using ascript in the virtual environment's binary directory. The invocation of thescript is platform-specific (`<venv>` must be replaced by the path of thedirectory containing the virtual environment):+-------------+-----------------+-----------------------------------------+| Platform | Shell | Command to activate virtual environment |+=============+=================+=========================================+| POSIX | bash/zsh | $ source <venv>/bin/activate |+-------------+-----------------+-----------------------------------------+| | fish | $ . <venv>/bin/activate.fish |+-------------+-----------------+-----------------------------------------+| | csh/tcsh | $ source <venv>/bin/activate.csh |+-------------+-----------------+-----------------------------------------+| | PowerShell Core | $ <venv>/bin/Activate.ps1 |+-------------+-----------------+-----------------------------------------+| Windows | cmd.exe | C:\\> <venv>\\Scripts\\activate.bat |+-------------+-----------------+-----------------------------------------+| | PowerShell | PS C:\\> <venv>\\Scripts\\Activate.ps1 |+-------------+-----------------+-----------------------------------------+You don't specifically *need* to activate an environment; activation justprepends the virtual environment's binary directory to your path, so that"python" invokes the virtual environment's Python interpreter and you can runinstalled scripts without having to use their full path. However, all scriptsinstalled in a virtual environment should be runnable without activating it,and run with the virtual environment's Python automatically.You can deactivate a virtual environment by typing "deactivate" in your shell.The exact mechanism is platform-specific and is an internal implementationdetail (typically a script or shell function will be used)... versionadded:: 3.4``fish`` and ``csh`` activation scripts... versionadded:: 3.8PowerShell activation scripts installed under POSIX for PowerShell Coresupport.
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