Metadata-Version: 1.0
Name: virtualenv
Version: 1.1
Summary: Virtual Python Environment builder
Home-page: http://pypi.python.org/pypi/virtualenv
Author: Ian Bicking
Author-email: ianb@colorstudy.com
License: MIT
Description: virtualenv
        ==========
        
        * `Discussion list <http://groups.google.com/group/python-virtualenv/>`_
        * `Bugs <https://bugs.launchpad.net/virtualenv/>`_
        
        .. contents::
        
        Status and License
        ------------------
        
        ``virtualenv`` is a successor to `workingenv
        <http://cheeseshop.python.org/pypi/workingenv.py>`_, and an extension
        of `virtual-python
        <http://peak.telecommunity.com/DevCenter/EasyInstall#creating-a-virtual-python>`_.
        
        It is written by Ian Bicking, and sponsored by the `Open Planning
        Project <http://topp.openplans.org>`_.  It is licensed under an
        `MIT-style permissive license
        <http://svn.colorstudy.com/virtualenv/trunk/docs/license.txt>`_.
        
        You can install it with ``easy_install virtualenv``, or from the
        `subversion repository
        <http://svn.colorstudy.com/virtualenv/trunk#egg=virtualenv-dev>`_ with
        ``easy_install virtualenv==dev``.
        
        What It Does
        ------------
        
        ``virtualenv`` is a tool to create isolated Python environments.
        
        The basic problem being addressed is one of dependencies and versions,
        and indirectly permissions.  Imagine you have an application that
        needs version 1 of LibFoo, but another application requires version
        2.  How can you use both these applications?  If you install
        everything into ``/usr/lib/python2.4/site-packages`` (or whatever your
        platform's standard location is), it's easy to end up in a situation
        where you unintentionally upgrade an application that shouldn't be
        upgraded.
        
        Or more generally, what if you want to install an application *and
        leave it be*?  If an application works, any change in its libraries or
        the versions of those libraries can break the application.
        
        Also, what if you can't install packages into the global
        ``site-packages`` directory?  For instance, on a shared host.
        
        In all these cases, ``virtualenv`` can help you.  It creates an
        environment that has its own installation directories, that doesn't
        share libraries with other virtualenv environments (and optionally
        doesn't use the globally installed libraries either).
        
        The basic usage is::
        
        $ python virtualenv.py ENV
        
        This creates ``ENV/lib/python2.4/site-packages`` (or
        ``ENV/lib/python2.5/site-packages`` on Python 2.5, etc), where any
        libraries you install will go.  It also creates ``ENV/bin/python``,
        which is a Python interpreter that uses this environment.  Anytime you
        use that interpreter (including when a script has
        ``#!/path/to/ENV/bin/python`` in it) the libraries in that environment
        will be used.  (**Note for Windows:** scripts and executables on
        Windows go in ``ENV\Scripts\``; everywhere you see ``bin/`` replace it
        with ``Scripts\``)
        
        It also installs `Setuptools
        <http://peak.telecommunity.com/DevCenter/setuptools>`_ for you, and if
        you use ``ENV/bin/easy_install`` the packages will be installed into
        the environment.
        
        Creating Your Own Bootstrap Scripts
        -----------------------------------
        
        While this creates an environment, it doesn't put anything into the
        environment.  Developers may find it useful to distribute a script
        that sets up a particular environment, for example a script that
        installs a particular web application.
        
        To create a script like this, call
        ``virtualenv.create_bootstrap_script(extra_text)``, and write the
        result to your new bootstrapping script.  Here's the documentation
        from the docstring:
        
        Creates a bootstrap script, which is like this script but with
        extend_parser, adjust_options, and after_install hooks.
        
        This returns a string that (written to disk of course) can be used
        as a bootstrap script with your own customizations.  The script
        will be the standard virtualenv.py script, with your extra text
        added (your extra text should be Python code).
        
        If you include these functions, they will be called:
        
        ``extend_parser(optparse_parser)``:
        You can add or remove options from the parser here.
        
        ``adjust_options(options, args)``:
        You can change options here, or change the args (if you accept
        different kinds of arguments, be sure you modify ``args`` so it is
        only ``[DEST_DIR]``).
        
        ``after_install(options, home_dir)``:
        
        After everything is installed, this function is called.  This
        is probably the function you are most likely to use.  An
        example would be::
        
        def after_install(options, home_dir):
        subprocess.call([join(home_dir, 'bin', 'easy_install'),
        'MyPackage'])
        subprocess.call([join(home_dir, 'bin', 'my-package-script'),
        'setup', home_dir])
        
        This example immediately installs a package, and runs a setup
        script from that package.
        
        Bootstrap Example
        ~~~~~~~~~~~~~~~~~
        
        Here's a more concrete example of how you could use this::
        
        import virtualenv, textwrap
        output = virtualenv.create_bootstrap_script(textwrap.dedent("""
        import os, subprocess
        def after_install(options, home_dir):
        etc = join(home_dir, 'etc')
        if not os.path.exists(etc):
        os.makedirs(etc)
        subprocess.call([join(home_dir, 'bin', 'easy_install'),
        'BlogApplication'])
        subprocess.call([join(home_dir, 'bin', 'paster'),
        'make-config', 'BlogApplication',
        join(etc, 'blog.ini')])
        subprocess.call([join(home_dir, 'bin', 'paster'),
        'setup-app', join(etc, 'blog.ini')])
        """))
        f = open('blog-bootstrap.py', 'w').write(output)
        
        Another example is available `here
        <https://svn.openplans.org/svn/fassembler/trunk/fassembler/create-venv-script.py>`_.
        
        activate script
        ~~~~~~~~~~~~~~~
        
        In a newly created virtualenv there will be a ``bin/activate`` shell
        script, or a ``Scripts/activate.bat`` batch file on Windows.
        
        On Posix systems you can do::
        
        $ source bin/activate
        
        This will change your ``$PATH`` to point to the virtualenv ``bin/``
        directory, and update your prompt.  Unlike workingenv, this is all it
        does; it's a convenience.  But if you use the complete path like
        ``/path/to/env/bin/python script.py`` you do not need to activate the
        environment first.  You have to use ``source`` because it changes the
        environment in-place.  After activating an environment you can use the
        function ``deactivate`` to undo the changes.
        
        On Windows you just do::
        
        > \path\to\env\bin\activate.bat
        
        And use ``deactivate.bat`` to undo the changes.
        
        The ``--no-site-packages`` Option
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        
        If you build with ``virtualenv --no-site-packages ENV`` it will *not*
        inherit any packages from ``/usr/lib/python2.5/site-packages`` (or
        wherever your global site-packages directory is).  This can be used if
        you don't have control over site-packages and don't want to depend on
        the packages there, or you just want more isolation from the global
        system.
        
        Using Virtualenv without ``bin/python``
        ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
        
        Sometimes you can't or don't want to use the Python interpreter
        created by the virtualenv.  For instance, in a `mod_python
        <http://www.modpython.org/>`_ or `mod_wsgi <http://www.modwsgi.org/>`_
        environment, there is only one interpreter.
        
        Luckily, it's easy.  You must use the custom Python interpreter to
        *install* libraries.  But to *use* libraries, you just have to be sure
        the path is correct.  Adding the correct path is easy::
        
        import site
        site.addsitedir('/path/to/virtualenv/lib/python2.5/site-packages')
        
        Using this you can have your isolated working environment, using the
        custom Python interpreter, but treat the result as just a simple set
        of libraries when running your application.
        
        Compare & Contrast with Alternatives
        ------------------------------------
        
        There are several alternatives that create isolated environments:
        
        * ``workingenv`` (which I do not suggest you use anymore *if*
        virtualenv works on your platform) is the predecessor to this
        library.  It used the main Python interpreter, but relied on setting
        ``$PYTHONPATH`` to activate the environment.  This causes problems
        when running Python scripts that aren't part of the environment
        (e.g., a globally installed ``hg`` or ``bzr``).  It also conflicted
        a lot with Setuptools.
        
        * `virtual-python
        <http://peak.telecommunity.com/DevCenter/EasyInstall#creating-a-virtual-python>`_
        is also a predecessor to this library.  It uses only symlinks, so it
        couldn't work on Windows.  It also symlinks over the *entire*
        standard library and global ``site-packages``.  As a result, it
        won't see new additions to the global ``site-packages``.
        
        This script only symlinks a small portion of the standard library
        into the environment, and so Windows it is feasible to simply copy
        these files over.  Also, it creates a new/empty ``site-packages``
        and also adds the global ``site-packages`` to the path, so updates
        are tracked separately.  This script also installs Setuptools
        automatically, saving a step and avoiding the need for network
        access.
        
        * `zc.buildout <http://pypi.python.org/pypi/zc.buildout>`_ doesn't
        create an isolated Python environment in the same style, but
        achieves similar results through a declarative config file that sets
        up scripts with very particular packages.  As a declarative system,
        it is somewhat easier to repeat and manage, but more difficult to
        experiment with.  ``zc.buildout`` includes the ability to setup
        non-Python systems (e.g., a database server or an Apache instance).
        
        I *strongly* recommend anyone doing application development or
        deployment use one of these tools.
        
        Other Documentation
        -------------------
        
        * James Gardner has written a tutorial on using `virtualenv with
        Pylons
        <http://wiki.pylonshq.com/display/pylonscookbook/Using+a+Virtualenv+Sandbox>`_.
        
        * `Blog announcement
        <http://blog.ianbicking.org/2007/10/10/workingenv-is-dead-long-live-virtualenv/>`_.
        
        Changes & News
        --------------
        
        1.1
        ~~~
        
        * Added support for Python 2.6.
        * Fix a problem with missing ``DLLs/zlib.pyd`` on Windows.  Create
        * ``bin/python`` (or ``bin/python.exe``) even when you run virtualenv
        with an interpreter named, e.g., ``python2.4``
        * Fix MacPorts Python
        * Added --unzip-setuptools option
        * Update to Setuptools 0.6c8
        * If the current directory is not writable, run ez_setup.py in ``/tmp``
        * Copy or symlink over the ``include`` directory so that packages will
        more consistently compile.
        
        1.0
        ~~~
        
        * Fix build on systems that use ``/usr/lib64``, distinct from
        ``/usr/lib`` (specifically CentOS x64).
        * Fixed bug in ``--clear``.
        * Fixed typos in ``deactivate.bat``.
        * Preserve ``$PYTHONPATH`` when calling subprocesses.
        
        0.9.2
        ~~~~~
        
        * Fix include dir copying on Windows (makes compiling possible).
        * Include the main ``lib-tk`` in the path.
        * Patch ``distutils.sysconfig``: ``get_python_inc`` and
        ``get_python_lib`` to point to the global locations.
        * Install ``distutils.cfg`` before Setuptools, so that system
        customizations of ``distutils.cfg`` won't effect the installation.
        * Add ``bin/pythonX.Y`` to the virtualenv (in addition to
        ``bin/python``).
        * Fixed an issue with Mac Framework Python builds, and absolute paths
        (from Ronald Oussoren).
        
        0.9.1
        ~~~~~
        
        * Improve ability to create a virtualenv from inside a virtualenv.
        * Fix a little bug in ``bin/activate``.
        * Actually get ``distutils.cfg`` to work reliably.
        
        0.9
        ~~~
        
        * Added ``lib-dynload`` and ``config`` to things that need to be
        copied over in an environment.
        * Copy over or symlink the ``include`` directory, so that you can
        build packages that need the C headers.
        * Include a ``distutils`` package, so you can locally update
        ``distutils.cfg`` (in ``lib/pythonX.Y/distutils/distutils.cfg``).
        * Better avoid downloading Setuptools, and hitting PyPI on environment
        creation.
        * Fix a problem creating a ``lib64/`` directory.
        * Should work on MacOSX Framework builds (the default Python
        installations on Mac).  Thanks to Ronald Oussoren.
        
        0.8.4
        ~~~~~
        
        * Windows installs would sometimes give errors about ``sys.prefix`` that
        were inaccurate.
        * Slightly prettier output.
        
        0.8.3
        ~~~~~
        
        * Added support for Windows.
        
        0.8.2
        ~~~~~
        
        * Give a better warning if you are on an unsupported platform (Mac
        Framework Pythons, and Windows).
        * Give error about running while inside a workingenv.
        * Give better error message about Python 2.3.
        
        0.8.1
        ~~~~~
        
        Fixed packaging of the library.
        
        0.8
        ~~~
        
        Initial release.  Everything is changed and new!
Keywords: setuptools deployment installation distutils
Platform: UNKNOWN
Classifier: Development Status :: 4 - Beta
Classifier: Intended Audience :: Developers
Classifier: License :: OSI Approved :: MIT License