6. The Python Package Index (PyPI)
**********************************

The Python Package Index (PyPI) stores meta-data describing
distributions packaged with distutils, as well as package data like
distribution files if a package author wishes.

Distutils provides the **register** and **upload** commands for
pushing meta-data and distribution files to PyPI, respectively.  See
Distutils commands for information on these commands.


6.1. PyPI overview
==================

PyPI lets you submit any number of versions of your distribution to
the index. If you alter the meta-data for a particular version, you
can submit it again and the index will be updated.

PyPI holds a record for each (name, version) combination submitted.
The first user to submit information for a given name is designated
the Owner of that name.  Changes can be submitted through the
**register** command or through the web interface.  Owners can
designate other users as Owners or Maintainers.  Maintainers can edit
the package information, but not designate new Owners or Maintainers.

By default PyPI displays only the newest version of a given package.
The web interface lets one change this default behavior and manually
select which versions to display and hide.

For each version, PyPI displays a home page.  The home page is created
from the "long_description" which can be submitted via the
**register** command.  See PyPI package display for more information.


6.2. Distutils commands
=======================

Distutils exposes two commands for submitting package data to PyPI:
the register command for submitting meta-data to PyPI and the upload
command for submitting distribution files.  Both commands read
configuration data from a special file called a .pypirc file.


6.2.1. The "register" command
-----------------------------

The distutils command **register** is used to submit your
distribution’s meta-data to an index server. It is invoked as follows:

   python setup.py register

Distutils will respond with the following prompt:

   running register
   We need to know who you are, so please choose either:
       1. use your existing login,
       2. register as a new user,
       3. have the server generate a new password for you (and email it to you), or
       4. quit
   Your selection [default 1]:

Note: if your username and password are saved locally, you will not
see this menu.  Also, refer to The .pypirc file for how to store your
credentials in a ".pypirc" file.

If you have not registered with PyPI, then you will need to do so now.
You should choose option 2, and enter your details as required. Soon
after submitting your details, you will receive an email which will be
used to confirm your registration.

Once you are registered, you may choose option 1 from the menu. You
will be prompted for your PyPI username and password, and **register**
will then submit your meta-data to the index.

See Additional command options for options to the **register**
command.


6.2.2. The "upload" command
---------------------------

The distutils command **upload** pushes the distribution files to
PyPI.

The command is invoked immediately after building one or more
distribution files.  For example, the command

   python setup.py sdist bdist_wininst upload

will cause the source distribution and the Windows installer to be
uploaded to PyPI.  Note that these will be uploaded even if they are
built using an earlier invocation of "setup.py", but that only
distributions named on the command line for the invocation including
the **upload** command are uploaded.

If a **register** command was previously called in the same command,
and if the password was entered in the prompt, **upload** will reuse
the entered password.  This is useful if you do not want to store a
password in clear text in a ".pypirc" file.

You can use the "--sign" option to tell **upload** to sign each
uploaded file using GPG (GNU Privacy Guard).  The  **gpg** program
must be available for execution on the system "PATH".  You can also
specify which key to use for signing using the "--identity=name"
option.

See Additional command options for additional options to the
**upload** command.


6.2.3. Additional command options
---------------------------------

This section describes options common to both the **register** and
**upload** commands.

The "--repository" or "-r" option lets you specify a PyPI server
different from the default.  For example:

   python setup.py sdist bdist_wininst upload -r https://example.com/pypi

For convenience, a name can be used in place of the URL when the
".pypirc" file is configured to do so.  For example:

   python setup.py register -r other

See The .pypirc file for more information on defining alternate
servers.

The "--show-response" option displays the full response text from the
PyPI server, which is useful when debugging problems with registering
and uploading.


6.2.4. The ".pypirc" file
-------------------------

The **register** and **upload** commands both check for the existence
of a ".pypirc" file at the location "$HOME/.pypirc". If this file
exists, the command uses the username, password, and repository URL
configured in the file.  The format of a ".pypirc" file is as follows:

   [distutils]
   index-servers =
       pypi

   [pypi]
   repository: <repository-url>
   username: <username>
   password: <password>

The *distutils* section defines an *index-servers* variable that lists
the name of all sections describing a repository.

Each section describing a repository defines three variables:

* *repository*, that defines the url of the PyPI server. Defaults to

     "https://upload.pypi.org/legacy/".

* *username*, which is the registered username on the PyPI server.

* *password*, that will be used to authenticate. If omitted the user

     will be prompt to type it when needed.

If you want to define another server a new section can be created and
listed in the *index-servers* variable:

   [distutils]
   index-servers =
       pypi
       other

   [pypi]
   repository: <repository-url>
   username: <username>
   password: <password>

   [other]
   repository: https://example.com/pypi
   username: <username>
   password: <password>

This allows the **register** and **upload** commands to be called with
the "--repository" option as described in Additional command options.

Specifically, you might want to add the PyPI Test Repository to your
".pypirc" to facilitate testing before doing your first upload to
"PyPI" itself.


6.3. PyPI package display
=========================

The "long_description" field plays a special role at PyPI. It is used
by the server to display a home page for the registered package.

If you use the reStructuredText syntax for this field, PyPI will parse
it and display an HTML output for the package home page.

The "long_description" field can be attached to a text file located in
the package:

   from distutils.core import setup

   with open('README.txt') as file:
       long_description = file.read()

   setup(name='Distutils',
         long_description=long_description)

In that case, "README.txt" is a regular reStructuredText text file
located in the root of the package besides "setup.py".

To prevent registering broken reStructuredText content, you can use
the **rst2html** program that is provided by the "docutils" package
and check the "long_description" from the command line:

   $ python setup.py --long-description | rst2html.py > output.html

"docutils" will display a warning if there’s something wrong with your
syntax.  Because PyPI applies additional checks (e.g. by passing "--
no-raw" to "rst2html.py" in the command above), being able to run the
command above without warnings does not guarantee that PyPI will
convert the content successfully.
