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John Del Rosario
129 lines
3.2 KiB
ReStructuredText
129 lines
3.2 KiB
ReStructuredText
Virtual Environments
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====================
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A Virtual Environment, put simply, is an isolated working copy of Python which
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allows you to work on a specific project without worry of affecting other
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projects.
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For example, you can work on a project which requires Django 1.3 while also
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maintaining a project which requires Django 1.0.
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virtualenv
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----------
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`virtualenv <http://pypi.python.org/pypi/virtualenv>`_ is a tool to create
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isolated Python environments.
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Install it via pip:
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.. code-block:: console
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$ pip install virtualenv
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Basic Usage
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~~~~~~~~~~~
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1. Create a virtual environment:
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.. code-block:: console
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$ virtualenv venv
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This creates a copy of Python in whichever directory you ran the command in,
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placing it in a folder named ``venv``.
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2. To begin using the virtual environment, it needs to be activated:
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.. code-block:: console
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$ source venv/bin/activate
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You can then begin installing any new modules without affecting the system
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default Python or other virtual environments.
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3. If you are done working in the virtual environment for the moment, you can
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deactivate it:
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.. code-block:: console
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$ deactivate
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This puts you back to the system's default Python interpreter with all its
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installed libraries.
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To delete a virtual environment, just delete its folder.
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After a while, though, you might end up with a lot of virtual environments
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littered across your system, and its possible you'll forget their names or
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where they were placed.
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virtualenvwrapper
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-----------------
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`virtualenvwrapper <http://www.doughellmann.com/projects/virtualenvwrapper/>`_
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provides a set of commands which makes working with virtual environments much
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more pleasant. It also places all your virtual environments in one place.
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To install (make sure **virtualenv** is already installed):
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.. code-block:: console
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$ pip install virtualenvwrapper
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$ export WORKON_HOME=~/Envs
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$ source /usr/local/bin/virtualenvwrapper.sh
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(`Full virtualenvwrapper install instructions <http://www.doughellmann.com/docs/virtualenvwrapper/#introduction>`_.)
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Basic Usage
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~~~~~~~~~~~
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1. Create a virtual environment:
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.. code-block:: console
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$ mkvirtualenv venv
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This creates the ``venv`` folder inside ``~/Envs``.
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2. Work on a virtual environment:
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.. code-block:: console
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$ workon venv
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**virtualenvwrapper** provides tab-completion on environment names. It really
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helps when you have a lot of environments and have trouble remembering their
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names.
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``workon`` also deactivates whatever environment you are currently in, so you
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can quickly switch between environments.
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3. Deactivating is still the same:
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.. code-block:: console
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$ deactivate
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4. To delete:
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.. code-block:: console
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$ rmvirtualenv venv
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Other useful commands
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~~~~~~~~~~~~~~~~~~~~~
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``lsvirtualenv``
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List all of the environments.
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``cdvirtualenv``
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Navigate into the directory of the currently activated virtual environment,
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so you can browse its ``site-packages``, for example.
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``cdsitepackages``
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Like the above, but directly into ``site-packages`` directory.
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``lssitepackages``
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Shows contents of ``site-packages`` directory.
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`Full list of virtualenvwrapper commands <http://www.doughellmann.com/docs/virtualenvwrapper/command_ref.html#managing-environments>`_.
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