fix: ensure compatibility with PEP 440 for pre-releases of Python packages

https://peps.python.org/pep-0440/#pre-releases

Author: mbdevpl

test/examples.py

@@ -70,7 +70,10 @@ def _remove_version_suffixes(path: pathlib.Path) -> t.Optional[pathlib.Path]:
     '1': ((1,), {}),
     '1.0': ((1, 0), {}),
     '1.0.0': ((1, 0, 0), {}),
+    '1.0.0rc1': ((1, 0, 0, None, 'rc', 1), {}),
+    '1.0.0rc2': ((1, 0, 0, None, 'rc', 2), {}),
     '1.0.0.rc2': ((1, 0, 0, '.', 'rc', 2), {}),
+    '1.0.0rc3': ((1, 0, 0, None, 'rc', 3), {}),
     '1.0.0.rc3': ((1, 0, 0, ('.', 'rc', 3)), {}),
     '1.0.0.rc2+local': ((1, 0, 0, '.', 'rc', 2, 'local'), {}),
     '1.0.0.rc3+local': ((1, 0, 0, ('.', 'rc', 3), 'local'), {}),
@@ -126,14 +129,16 @@ def _remove_version_suffixes(path: pathlib.Path) -> t.Optional[pathlib.Path]:
     '1.0.0.4': ((1, 0, 0, '.', None, 4), {}),
     '2.0.0.8+cc81cee': ((2, 0, 0, '.', None, 8, 'cc81cee'), {}),
     '4.5.0.dev1234': ((4, 5, 0, '.', 'dev', 1234), {}),
-    '1.0.0.rc3': ((1, 0, 0, '.', 'rc', 3), {}),
+    '1.0.0rc1': ((1, 0, 0, None, 'rc', 1), {}),
+    '1.0.0rc3': ((1, 0, 0, None, 'rc', 3), {}),
     '1.0.1.dev0': ((1, 0, 1, '.', 'dev', 0), {}),
     '0.4.4.dev5+84e1d430': ((0, 4, 4, '.', 'dev', 5, '84e1d430'), {}),
     '0.4.4.dev5+20171003.84e1d430': ((0, 4, 4, '.', 'dev', 5, '20171003', '.', '84e1d430'), {})}
 
 INCOMPATIBLE_STR_CASES: t.Dict[str, t.Tuple[tuple, dict]] = {
     '1.0.0-2': ((1, 0, 0, '-', None, 2), {}),
     # '1.0.0-0.2': ((1, 0, 0, '-', None, 0, '.', None, 2), {}),
+    '1.0.0.rc3': ((1, 0, 0, '.', 'rc', 3), {}),
     '4.5.0.dev': ((4, 5, 0, '.', 'dev', None), {})}
 
 STR_CASES = dict(itertools.chain(COMPATIBLE_STR_CASES.items(),

version_query/version.py

@@ -12,6 +12,8 @@
 
 _LOG = logging.getLogger(__name__)
 
+PY_PRE_RELEASE_INDICATORS = {'a', 'b', 'c', 'rc'}
+
 
 @enum.unique
 class VersionComponent(enum.IntEnum):
@@ -168,8 +170,8 @@ def from_py_version(cls, py_version: packaging.version.Version):
         elif ver.pre:
             pre_ver = ver.pre
         if pre_ver:
-            pre_release = [('.', pre_ver[0] if len(pre_ver) > 0 else None,
-                            pre_ver[1] if len(pre_ver) > 1 else None)]
+            prefix_dot = None if pre_ver[0] in PY_PRE_RELEASE_INDICATORS else '.'
+            pre_release = [(prefix_dot, pre_ver[0], pre_ver[1] if len(pre_ver) > 1 else None)]
         if ver.local:
             local = tuple(itertools.chain.from_iterable(
                 (dot, str(_)) for dot, _ in zip('.' * len(ver.local), ver.local)))[1:]
@@ -502,6 +504,8 @@ def _pre_release_segment_to_str(self, segment: int) -> str:
             return '{}{}'.format(*version_tuple[:2])
         if _version_tuple_checker(version_tuple, (True, False, True)):
             return f'{version_tuple[0]}{version_tuple[2]}'
+        if _version_tuple_checker(version_tuple, (False, True, True)):
+            return '{}{}'.format(*version_tuple[1:])
         if _version_tuple_checker(version_tuple, (True, True, True)):
             return '{}{}{}'.format(*version_tuple)
         raise ValueError(f'cannot generate valid version string from {repr(self)}')