1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
|
====================================
Building Astropy and its Subpackages
====================================
The build process currently uses the `setuptools
<https://bitbucket.org/pypa/setuptools>`_ package to build and install the
astropy core (and any affiliated packages that use the template). The user
doesn't necessarily need to have `setuptools`_ installed, as it will
automatically bootstrap itself using the ``ez_setup.py`` file in the source
distribution if it isn't installed for the user.
Astropy-helpers
---------------
As of Astropy v0.4, Astropy also uses an external package called
`astropy-helpers <https://github.com/astropy/astropy-helpers>`_ to provide some
of its build and installation functionality. A copy of astropy-helpers is
included with the Astropy source distribution, but also includes a mechanism to
automatically download bug fixes from PyPI. The reason for providing these
helpers as a separate package is that it makes it easier for affiliated
packages to take advantage of these same utilities without requiring Astropy to
be installed *first*. See `APE4
<https://github.com/astropy/astropy-APEs/blob/master/APE4.rst>`_ for the full
background on this.
Astropy-helpers is automatically bootstrapped to the Astropy build/installation
script (``setup.py``) via a script called ``ah_bootstrap.py`` that is imported
by ``setup.py``. This script will do its best to ensure that the user has an
up-to-date copy of astropy-helpers before building the package. The
auto-upgrade mechanism in particular allows pushing platform-specific fixes for
the build process without releasing a new version of Astropy (or any affiliated
package that uses astropy-helpers).
The behavior of the ``ah_bootstrap.py`` script can also be modified by options
in the project's ``setup.cfg`` file under a section called ``[ah_boostrap]``.
APE4 provides `more details
<https://github.com/astropy/astropy-APEs/blob/master/APE4.rst#astropy_helpers-bootstrap-script>`_.
The astropy-helpers distribution provides a Python package called
``astropy_helpers``. Code that previously referenced the modules
``astropy.setup_helpers`` and ``astropy.version_helpers`` should now depend on
astropy-helpers and use ``astrop_helpers.setup_helpers`` and
``astropy_helpers.version_helpers`` respectively. Likewise, astropy-helpers
includes tools for building Astropy's documentation. The ``astropy.sphinx``
package is deprecated in favor of ``astropy_helpers.sphinx``. As such,
astropy-helpers is a dependency of building Astropy's documentation.
Customizing setup/build for subpackages
---------------------------------------
As is typical, there is a single ``setup.py`` file that is used for the whole
``astropy`` package. To customize setup parameters for a given sub-package, a
``setup_package.py`` file can be defined inside a package, and if it is present,
the setup process will look for the following functions to customize the build
process:
* ``get_package_data``
This function, if defined, should return a dictionary mapping the name of
the subpackage(s) that need package data to a list of data file paths
(possibly including wildcards) relative to the path of the package's source
code. e.g. if the source distribution has a needed data file
``astropy/wcs/tests/data/3d_cd.hdr``, this function should return
``{'astropy.wcs.tests':['data/3d_cd.hdr']}``. See the ``package_data``
option of the :func:`distutils.core.setup` function.
It is recommended that all such data be in a directory named ``data`` inside
the package within which it is supposed to be used. This package data should
be accessed via the `astropy.utils.data.get_pkg_data_filename` and
`astropy.utils.data.get_pkg_data_fileobj` functions.
* ``get_extensions``
This provides information for building C or Cython extensions. If defined,
it should return a list of `distutils.core.Extension` objects controlling
the Cython/C build process (see below for more detail).
* ``get_build_options``
This function allows a package to add extra build options. It
should return a list of tuples, where each element has:
- *name*: The name of the option as it would appear on the
commandline or in the ``setup.cfg`` file.
- *doc*: A short doc string for the option, displayed by
``setup.py build --help``.
- *is_bool* (optional): When `True`, the option is a boolean
option and doesn't have an associated value.
Once an option has been added, its value can be looked up using
``astropy_helpers.setup_helpers.get_distutils_build_option``.
* ``get_external_libraries``
This function declares that the package uses libraries that are
included in the astropy distribution that may also be distributed
elsewhere on the users system. It should return a list of library
names. For each library, a new build option is created,
``'--use-system-X'`` which allows the user to request to use the
system's copy of the library. The package would typically call
``astropy_helpers.setup_helpers.use_system_library`` from its
``get_extensions`` function to determine if the package should use
the system library or the included one.
* ``requires_2to3``
This function declares whether the package requires processing
through the `2to3`_ tool to run on Python 3. If not included, it
defaults to `True`. The use of `2to3`_ is phased out in astropy
and is retained for use in affiliate packages which have not switched
to using `six`_ instead. See :ref:`dev-portable` for more information.
The ``astropy_helpers.setup_helpers`` modules includes an
``update_package_files`` function which automatically searches the given source
path for ``setup_package.py`` modules and calls each of the above functions, if
they exist. This makes it easy for affiliated packages to use this machinery
in their own ``setup.py``.
.. _six: http://pythonhosted.org/six/
.. _2to3: https://docs.python.org/2/library/2to3.html
|
