semver: allow constraints with trailing commas (again)

src/poetry/core/semver/helpers.py

@@ -18,6 +18,9 @@ def parse_constraint(constraints: str) -> VersionConstraint:
     or_constraints = re.split(r"\s*\|\|?\s*", constraints.strip())
     or_groups = []
     for constraints in or_constraints:
+        # allow trailing commas for robustness (even though it may not be
+        # standard-compliant it seems to occur in some packages)
+        constraints = constraints.rstrip(",").rstrip()
         and_constraints = re.split(
             "(?<!^)(?<![~=>< ,]) *(?<!-)[, ](?!-) *(?!,|$)", constraints
         )

tests/semver/test_helpers.py

@@ -347,6 +347,41 @@ def test_parse_constraints_negative_wildcard(
     assert parse_constraint(input) == constraint
 
 
+@pytest.mark.parametrize(
+    "input,constraint",
+    [
+        (">3.7,", VersionRange(min=Version.parse("3.7"))),
+        (">3.7 , ", VersionRange(min=Version.parse("3.7"))),
+        (
+            ">3.7,<3.8,",
+            VersionRange(min=Version.parse("3.7"), max=Version.parse("3.8")),
+        ),
+        (
+            ">3.7,||<3.6,",
+            VersionRange(min=Version.parse("3.7")).union(
+                VersionRange(max=Version.parse("3.6"))
+            ),
+        ),
+        (
+            ">3.7 , || <3.6 , ",
+            VersionRange(min=Version.parse("3.7")).union(
+                VersionRange(max=Version.parse("3.6"))
+            ),
+        ),
+        (
+            ">3.7, <3.8, || <3.6, >3.5",
+            VersionRange(min=Version.parse("3.7"), max=Version.parse("3.8")).union(
+                VersionRange(min=Version.parse("3.5"), max=Version.parse("3.6"))
+            ),
+        ),
+    ],
+)
+def test_parse_constraints_with_trailing_comma(
+    input: str, constraint: VersionRange
+) -> None:
+    assert parse_constraint(input) == constraint
+
+
 @pytest.mark.parametrize(
     "input, expected",
     [