Overview
========

This document describes the steps required to install IPython.  IPython is
organized into a number of subpackages, each of which has its own dependencies.
All of the subpackages come with IPython, so you don't need to download and
install them separately.  However, to use a given subpackage, you will need to
install all of its dependencies.


Please let us know if you have problems installing IPython or any of its
dependencies. Officially, IPython requires Python version 2.6 or 2.7.  There
is an experimental port of IPython for Python3 `on GitHub 
<https://github.com/ipython/ipython-py3k>`_

.. warning::

    Officially, IPython supports Python versions 2.6 and 2.7.

    IPython 0.11 has a hard syntax dependency on 2.6, and will no longer work
    on Python <= 2.5.

Some of the installation approaches use the :mod:`setuptools` package and its
:command:`easy_install` command line program.  In many scenarios, this provides
the most simple method of installing IPython and its dependencies.  It is not
required though.  More information about :mod:`setuptools` can be found on its
website.

.. note::

    On Windows, IPython *does* depend on :mod:`setuptools`, and it is recommended
    that you install the :mod:`distribute` package, which improves
    :mod:`setuptools` and fixes various bugs.
    
    We hope to remove this dependency in 0.12.

More general information about installing Python packages can be found in
Python's documentation at http://www.python.org/doc/.

Quickstart
==========

If you have :mod:`setuptools` installed and you are on OS X or Linux (not
Windows), the following will download and install IPython *and* the main
optional dependencies:

.. code-block:: bash

    $ easy_install ipython[zmq,test]

This will get pyzmq, which is needed for
IPython's parallel computing features as well as the nose package, which will
enable you to run IPython's test suite.  

To run IPython's test suite, use the :command:`iptest` command:

.. code-block:: bash

    $ iptest

Read on for more specific details and instructions for Windows.

Installing IPython itself
=========================

Given a properly built Python, the basic interactive IPython shell will work
with no external dependencies.  However, some Python distributions
(particularly on Windows and OS X), don't come with a working :mod:`readline`
module.  The IPython shell will work without :mod:`readline`, but will lack
many features that users depend on, such as tab completion and command line
editing.  If you install IPython with :mod:`setuptools`, (e.g. with `easy_install`),
then the appropriate :mod:`readline` for your platform will be installed.
See below for details of how to make sure you have a working :mod:`readline`.

Installation using easy_install
-------------------------------

If you have :mod:`setuptools` installed, the easiest way of getting IPython is
to simple use :command:`easy_install`:

.. code-block:: bash

    $ easy_install ipython

That's it.

Installation from source
------------------------

If you don't want to use :command:`easy_install`, or don't have it installed,
just grab the latest stable build of IPython from `here
<https://github.com/ipython/ipython/downloads>`_.  Then do the following:

.. code-block:: bash

    $ tar -xzf ipython.tar.gz
    $ cd ipython
    $ python setup.py install

If you are installing to a location (like ``/usr/local``) that requires higher
permissions, you may need to run the last command with :command:`sudo`.

Windows
-------

.. note::

    On Windows, IPython requires :mod:`setuptools` or :mod:`distribute`.
    
    We hope to remove this dependency in 0.12.

There are a few caveats for Windows users.  The main issue is that a basic
``python setup.py install`` approach won't create ``.bat`` file or Start Menu
shortcuts, which most users want.  To get an installation with these, you can
use any of the following alternatives:

1. Install using :command:`easy_install`.

2. Install using our binary ``.exe`` Windows installer, which can be found
   `here <http://ipython.scipy.org/dist/>`_

3. Install from source, but using :mod:`setuptools` (``python setupegg.py
   install``).

IPython by default runs in a terminal window, but the normal terminal
application supplied by Microsoft Windows is very primitive.  You may want to
download the excellent and free Console_ application instead, which is a far
superior tool.  You can even configure Console to give you by default an
IPython tab, which is very convenient to create new IPython sessions directly
from the working terminal.

.. _Console:  http://sourceforge.net/projects/console

Note for Windows 64 bit users: you may have difficulties with the stock
installer on 64 bit systems; in this case (since we currently do not have 64
bit builds of the Windows installer) your best bet is to install from source
with the setuptools method indicated in #3 above.  See `this bug report`_ for
further details.

.. _this bug report: https://bugs.launchpad.net/ipython/+bug/382214

   
Installing the development version
----------------------------------

It is also possible to install the development version of IPython from our
`Git <http://git-scm.com/>`_ source code repository.  To do this you will
need to have Git installed on your system.  Then just do:

.. code-block:: bash

    $ git clone https://github.com/ipython/ipython.git
    $ cd ipython
    $ python setup.py install

Again, this last step on Windows won't create ``.bat`` files or Start Menu
shortcuts, so you will have to use one of the other approaches listed above.

Some users want to be able to follow the development branch as it changes.  If
you have :mod:`setuptools` installed, this is easy. Simply replace the last
step by:

.. code-block:: bash

    $ python setupegg.py develop

This creates links in the right places and installs the command line script to
the appropriate places.  Then, if you want to update your IPython at any time,
just do:

.. code-block:: bash

    $ git pull

Basic optional dependencies
===========================

There are a number of basic optional dependencies that most users will want to
get.  These are:

* readline (for command line editing, tab completion, etc.)
* nose (to run the IPython test suite)
* pexpect (to use things like irunner)

If you are comfortable installing these things yourself, have at it, otherwise
read on for more details.

readline
--------

In principle, all Python distributions should come with a working
:mod:`readline` module.  But, reality is not quite that simple.  There are two
common situations where you won't have a working :mod:`readline` module:

* If you are using the built-in Python on Mac OS X.

* If you are running Windows, which doesn't have a :mod:`readline` module.

When IPython is installed with :mod:`setuptools`, (e.g. with `easy_install`),
readline is added as a dependency on OS X, and PyReadline on Windows, and will
be installed on your system.  However, if you do not use setuptools, you may
have to install one of these packages yourself.

On OS X, the built-in Python doesn't not have :mod:`readline` because of
license issues.  Starting with OS X 10.5 (Leopard), Apple's built-in Python has
a BSD-licensed not-quite-compatible readline replacement. As of IPython 0.9,
many of the issues related to the differences between readline and libedit seem
to have been resolved.  While you may find libedit sufficient, we have
occasional reports of bugs with it and several developers who use OS X as their
main environment consider libedit unacceptable for productive, regular use with
IPython.

Therefore, we *strongly* recommend that on OS X you get the full
:mod:`readline` module.  We will *not* consider completion/history problems to
be bugs for IPython if you are using libedit.

To get a working :mod:`readline` module, just do (with :mod:`setuptools`
installed):

.. code-block:: bash

    $ easy_install readline

.. note::

    Other Python distributions on OS X (such as fink, MacPorts and the official
    python.org binaries) already have readline installed so you likely don't
    have to do this step.

If needed, the readline egg can be build and installed from source (see the
wiki page at http://ipython.scipy.org/moin/InstallationOSXLeopard).

On Windows, you will need the PyReadline module. PyReadline is a separate,
Windows only implementation of readline that uses native Windows calls through
:mod:`ctypes`. The easiest way of installing PyReadline is you use the binary
installer available `here <https://launchpad.net/pyreadline/+download>`_.

nose
----

To run the IPython test suite you will need the :mod:`nose` package.  Nose
provides a great way of sniffing out and running all of the IPython tests.  The
simplest way of getting nose, is to use :command:`easy_install`:

.. code-block:: bash

    $ easy_install nose

Another way of getting this is to do:

.. code-block:: bash

    $ easy_install ipython[test]

For more installation options, see the `nose website
<http://somethingaboutorange.com/mrl/projects/nose/>`_.  

Once you have nose installed, you can run IPython's test suite using the
iptest command:

.. code-block:: bash

    $ iptest

pexpect
-------

The pexpect package is used in IPython's :command:`irunner` script, as well as
for managing subprocesses [pexpect]_. IPython now includes a version of pexpect
in :mod:`IPython.external`, but if you have installed pexpect, IPython will use
that instead. On Unix platforms (including OS X), just do:

.. code-block:: bash

    $ easy_install pexpect

Windows users are out of luck as pexpect does not run there.

Dependencies for IPython.parallel (parallel computing)
======================================================

:mod:`IPython.kernel` has been replaced by :mod:`IPython.parallel`, 
which uses ZeroMQ for all communication.

IPython.parallel provides a nice architecture for parallel computing.  The
main focus of this architecture is on interactive parallel computing.  These
features require just one package: pyzmq.  See the next section for pyzmq
details.

On a Unix style platform (including OS X), if you want to use
:mod:`setuptools`, you can just do:

.. code-block:: bash

    $ easy_install ipython[zmq]    # will include pyzmq

Security in IPython.parallel is provided by SSH tunnels.  By default, Linux
and OSX clients will use the shell ssh command, but on Windows, we also
support tunneling with paramiko [paramiko]_.

Dependencies for IPython.zmq
============================

pyzmq
-----

IPython 0.11 introduced some new functionality, including a two-process
execution model using ZeroMQ for communication [ZeroMQ]_. The Python bindings
to ZeroMQ are found in the pyzmq project, which is easy_install-able once you
have ZeroMQ installed.  If you are on Python 2.6 or 2.7 on OSX, or 2.7 on Windows,
pyzmq has eggs that include ZeroMQ itself.

IPython.zmq depends on pyzmq >= 2.1.4.

Dependencies for ipython qtconsole (new GUI)
============================================

Qt
--

Also with 0.11, a new GUI was added using the work in :mod:`IPython.zmq`,
which can be launched with ``ipython qtconsole``. The GUI is built on Qt, and works
with either PyQt, which can be installed from the 
`PyQt website <http://www.riverbankcomputing.co.uk/>`_, or 
`PySide <http://www.pyside.org/>`_, from Nokia.

pygments
--------

The syntax-highlighting in ``ipython qtconsole`` is done with the pygments project, 
which is easy_install-able [pygments]_.

.. [ZeroMQ] ZeroMQ.  http://www.zeromq.org
.. [paramiko] paramiko. https://github.com/robey/paramiko
.. [pygments] Pygments syntax highlighting. http://pygments.org
.. [pexpect] Pexpect. http://www.noah.org/wiki/Pexpect
