Comply with PEP517 (#824)

 Add pep517check environment to tox

 Split version info into a separate file, load it using importlib

Fixes #823.

1 files changed, 53 insertions, 0 deletions

diff --git a/markdown/__meta__.py b/markdown/__meta__.py
new file mode 100644
index 0000000..fcbd47b
--- /dev/null
+++ b/markdown/__meta__.py
@@ -0,0 +1,53 @@
+# -*- coding: utf-8 -*-
+"""
+Python Markdown
+
+A Python implementation of John Gruber's Markdown.
+
+Documentation: https://python-markdown.github.io/
+GitHub: https://github.com/Python-Markdown/markdown/
+PyPI: https://pypi.org/project/Markdown/
+
+Started by Manfred Stienstra (http://www.dwerg.net/).
+Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+Currently maintained by Waylan Limberg (https://github.com/waylan),
+Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+Copyright 2007-2018 The Python Markdown Project (v. 1.7 and later)
+Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+Copyright 2004 Manfred Stienstra (the original version)
+
+License: BSD (see LICENSE.md for details).
+"""
+
+from pkg_resources.extern import packaging
+
+# __version_info__ format:
+# (major, minor, patch, dev/alpha/beta/rc/final, #)
+# (1, 1, 2, 'dev', 0) => "1.1.2.dev0"
+# (1, 1, 2, 'alpha', 1) => "1.1.2a1"
+# (1, 2, 0, 'beta', 2) => "1.2b2"
+# (1, 2, 0, 'rc', 4) => "1.2rc4"
+# (1, 2, 0, 'final', 0) => "1.2"
+__version_info__ = (3, 1, 0, 'final', 0)
+
+
+def _get_version():  # pragma: no cover
+    " Returns a PEP 440-compliant version number from version_info. "
+    assert len(__version_info__) == 5
+    assert __version_info__[3] in ('dev', 'alpha', 'beta', 'rc', 'final')
+
+    parts = 2 if __version_info__[2] == 0 else 3
+    v = '.'.join(map(str, __version_info__[:parts]))
+
+    if __version_info__[3] == 'dev':
+        v += '.dev' + str(__version_info__[4])
+    elif __version_info__[3] != 'final':
+        mapping = {'alpha': 'a', 'beta': 'b', 'rc': 'rc'}
+        v += mapping[__version_info__[3]] + str(__version_info__[4])
+
+    # Ensure version is valid and normalized
+    return str(packaging.version.Version(v))
+
+
+__version__ = _get_version()