release-info 0.3.6

automatically updated python release information

For various reasons you might want to know which Python versions are “current”:

• provide a list of pyXY targets to tox

• remove a no longer supported version of Python from the .whl files you generate to upload to PyPI

• determine which ‘Programming Language :: Python ::’ classifiers to include in your package information

• check if you have the latest micro version of a Python installed on all of your servers

extracting this kind of information from various PEPs (that often have slightly different formats), python.org and other web pages, is cumbersome. This package both provides a commandline utility python_release_info that you can use in scripts, makefiles, etc. and a programmatic interface to get to release information.

The release information is retrieved from the internet and can be updated e.g. on a daily basis, without having update the package itself. A Python based build script can check if one or more new versions are available for download and take action accordingly. Pre-release information can be queried as well.

The following is a commandline session from March 28th, 2020 ( which you can simulate by specifying --dd 2020-03-28):

$ /opt/python/3.8.2/bin/python -m venv --copies /opt/util/pri
$ source /opt/util/pri/bin/activate
(pri) $ pip install -U -q pip
(pri) $ pip install -q release_info
(pri) $ python_release_info current
2.7.17
3.5.9
3.6.10
3.7.7
3.8.2
(pri) $ python_release_info pre
3.9.0.a.5
(pri) $ echo $?    # 0 -> updated, 1 -> not updated
1
(pri) $ mkdir -p /opt/util/pri/tmp
(pri) $ python_release_info --dir /opt/util/pri/tmp update --extract
(pri) $ ls --classify /opt/util/pri/tmp
Python-3.8.2/  Python-3.8.2.tar.xz

If md5 information is available (true for all current and future versions), then the downloaded tar file is checked.

The script allows for all-in-one (update, download, extract build) using:

python_release_info update --dir /data/DOWNLOAD/cpython --extract --build='make -f ../Makefile'

this can be run on a recurring basis e.g. from a crontab. The script checks if there are one more new versions, and if there are, downloads the .tar.xz to /data/DOWNLOAD/cpython and checks the md5 sum of the downloaded file. Then it changes to that directory and extracts the tar file. After that it changes to the toplevel directory created by the extraction, sets the environment variable PYTHONVERSION to the extracted version and executes the argument to the --build option.

If this all-in-one solution doesn’t cover your needs, it is simple to write a commandline or Python program that suits your environment.

CONFIG FILE

Your config file normally is ~/.config/python_release_info/config.ini (i.e. follows XDG) except for Windows: %APPDATA%/python_release_info/config.ini.

The [INFO] section in that file allows you to add to, or overwrite, data in the automatically updated information:

[INFO]
add = xxx.pon
overwrite = yyy.pon

You can, but don’t have to, have either or both entries set. By default both are commented out. The files must have the same hierarchical structure as the release_info.pon, so it probably best to copy that file and delete what is not relevant, then update the rest.

The difference between the two is that when using add the data loaded from there does not overwrite already existing “paths” to leaf node data loaded from release_info.pon. You should use add for information that you expect to be incorporated in future automatic updates, and when it does get incorporated, you want to use that information. You should use overwrite e.g. when you found an error in the data and you cannot wait to have it fixed in the release_info repository and automatically downloaded.

So if you would have the following in the automatically updated release_info.pon ( in reality there is more data there):

dict(
  cpython={
    (3, 8): {
      (3, 8, 0): dict(rel=date(2019, 10, 14)),
      (3, 8, 1): dict(rel=date(2019, 12, 18)),
      (3, 8, 2): dict(rel=date(2020, 2, 24), md5='e9d6ebc92183a177b8e8a58cad5b8d67'),
    },
  }
)

and have the following in your xxx.pon file (to be added):

dict(
  cpython={
    (3, 8): {
      (3, 8, 0): dict(md5='dbac8df9d8b9edc678d0f4cacdb7dbb0'),
      (3, 8, 1): dict(rel=date(2019, 12, 25), md5='b3fb85fd479c0bf950c626ef80cacb57'),
      (3, 8, 3): dict(rel=date(2020, 5, 4)),
    },
  }
)

then the result would be like:

dict(
  cpython={
    (3, 8): {
      (3, 8, 0): dict(rel=date(2019, 10, 14), md5='dbac8df9d8b9edc678d0f4cacdb7dbb0'),
      (3, 8, 1): dict(rel=date(2019, 12, 18), md5='b3fb85fd479c0bf950c626ef80cacb57'),
      (3, 8, 2): dict(rel=date(2020, 2, 24), md5='e9d6ebc92183a177b8e8a58cad5b8d67'),
      (3, 8, 3): dict(rel=date(2020, 5, 4)),
    },
  }
)

but if the same content would be in yyy.pon (to be overwritten), then the result would be like:

dict(
  cpython={
    (3, 8): {
      (3, 8, 0): dict(rel=date(2019, 10, 14), md5='dbac8df9d8b9edc678d0f4cacdb7dbb0'),
      (3, 8, 1): dict(rel=date(2019, 12, 25), md5='b3fb85fd479c0bf950c626ef80cacb57'),
      (3, 8, 2): dict(rel=date(2020, 2, 24), md5='e9d6ebc92183a177b8e8a58cad5b8d67'),
      (3, 8, 3): dict(rel=date(2020, 5, 4)),
    },
  }
)

with the difference being in the date for release 3.8.1.

Setting defaults

You can set e.g. a default value value for the global --dir option in a section DEFAULTS in the config file:

[DEFAULTS]
dir = /opt/util/pri/tmp

This also works for the subparsers, you can e.g. always force a download:

[DEFAULTS.DOWNLOAD]
force = True

• The sections names in the config files are converted to lowercase so you can also use [defaults.download] or [Defaults.Download].

• The key/value entries are not converted, your key has to match the option (minus the --) exactly for a default to be set from the config file.

• Options provided on the commandline override those in the config file (there is currently no way to “un-force” from the commandline if force is set in the config file)

API

You can use the release information from your program:

import pathlib
from release_info import release_info

def download_and_extract_latest_micro_versions_non_end_of_life():
    ri = release_info()
    ri.download_data()
    latest = None
    for version in ri.find_current():
        url = ri.src_url(version)
        print(version, url)  # list the versions found
        latest = version
    # extract the last of the versions found
    path = pathlib.Path('/var/tmp')
    ri.download(latest, dir=path, extract=True)
    print(list(path.glob('Python*')))

def download_and_extract_new_versions_only():
    ri = release_info()
    for version in ri.download_data():
        path = pathlib.Path('/var/tmp/new')
        ri.download(latest, dir=path, extract=True)

download_and_extract_latest_micro_versions_non_end_of_life()

which shows:

(3, 7, 12) https://www.python.org/ftp/python/3.7.12/Python-3.7.12.tar.xz
(3, 8, 12) https://www.python.org/ftp/python/3.8.12/Python-3.8.12.tar.xz
(3, 9, 10) https://www.python.org/ftp/python/3.9.10/Python-3.9.10.tar.xz
(3, 10, 2) https://www.python.org/ftp/python/3.10.2/Python-3.10.2.tar.xz
[PosixPath('/var/tmp/Python-3.10.1'), PosixPath('/var/tmp/Python-3.10.1.tar.xz'), PosixPath('/var/tmp/Python-3.10.2'), PosixPath('/var/tmp/Python-3.10.2.tar.xz')]