6. The Python Package Index (PyPI)

Python 3.4

6. The Python Package Index (PyPI)

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

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 the .pypirc file. PyPI displays a home page for each package created from the long_description submitted by the register command.

6.1. Registering Packages

The distutils command register is used to submit your distribution’s meta-data to the index. 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.

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.

You may submit any number of versions of your distribution to the index. If you alter the meta-data for a particular version, you may 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. They may submit changes through the register command or through the web interface. They may also designate other users as Owners or Maintainers. Maintainers may edit the package information, but not designate other 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.

6.2. Uploading Packages

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.

The upload command uses the username, password, and repository URL from the $HOME/.pypirc file (see section The .pypirc file for more on this file). 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 clear text password in the $HOME/.pypirc file.

You can specify another PyPI server with the --repository=url option:

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

See section The .pypirc file for more on defining several servers.

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.

Other upload options include --repository=url or --repository=section where url is the url of the server and section the name of the section in $HOME/.pypirc, and --show-response (which displays the full response text from the PyPI server for help in debugging upload problems).

6.3. The .pypirc file

The format of the .pypirc file is as follows:

[distutils]
index-servers =
    pypi

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

The distutils section defines a 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

    http://www.python.org/pypi.

  • 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: http://example.com/pypi
username: <username>
password: <password>

register can then be called with the -r option to point the repository to work with:

python setup.py register -r http://example.com/pypi

For convenience, the name of the section that describes the repository may also be used:

python setup.py register -r other

6.4. 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.