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John Louis Del Rosario
106 lines
2.9 KiB
ReStructuredText
106 lines
2.9 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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$ 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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$ virtualenv ENVIRONMENT_NAME
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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 ``ENVIRONMENT_NAME``.
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2. To begin using the virtual environment, it needs to be activated::
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$ source ENVIRONMENT_NAME/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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$ 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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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 into one place.
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To install (make sure **virtualenv** is already installed)::
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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 instructions `here <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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$ mkvirtualenv ENVIRONMENT_NAME
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This creates the ``ENVIRONMENT_NAME`` folder inside ``~/Envs``.
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2. Work on a virtual environment::
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$ workon ENVIRONMENT_NAME
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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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$ deactivate
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4. To delete::
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$ rmvirtualenv ENVIRONMENT_NAME
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Other nifty commands include:
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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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A full list of commands can be found `here <http://www.doughellmann.com/docs/virtualenvwrapper/command_ref.html#managing-environments>`_.
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