Merge pull request #3466 from effigies/fix/looseversion_compat

FIX: Make vendored LooseVersion comparable to distutils.version.LooseVersion

Author: effigies

nipype/external/tests/test_version.py

@@ -0,0 +1,35 @@
+import warnings
+
+import pytest
+
+from nipype.external.version import LooseVersion as Vendored
+
+with warnings.catch_warnings():
+    warnings.simplefilter("ignore")
+    try:
+        from distutils.version import LooseVersion as Original
+    except ImportError:
+        pytest.skip()
+
+
+@pytest.mark.parametrize("v1, v2", [("0.0.0", "0.0.0"), ("0.0.0", "1.0.0")])
+def test_LooseVersion_compat(v1, v2):
+    vend1, vend2 = Vendored(v1), Vendored(v2)
+    with warnings.catch_warnings():
+        warnings.simplefilter("ignore")
+        orig1, orig2 = Original(v1), Original(v2)
+
+    assert vend1 == orig1
+    assert orig1 == vend1
+    assert vend2 == orig2
+    assert orig2 == vend2
+    assert (vend1 == orig2) == (v1 == v2)
+    assert (vend1 < orig2) == (v1 < v2)
+    assert (vend1 > orig2) == (v1 > v2)
+    assert (vend1 <= orig2) == (v1 <= v2)
+    assert (vend1 >= orig2) == (v1 >= v2)
+    assert (orig1 == vend2) == (v1 == v2)
+    assert (orig1 < vend2) == (v1 < v2)
+    assert (orig1 > vend2) == (v1 > v2)
+    assert (orig1 <= vend2) == (v1 <= v2)
+    assert (orig1 >= vend2) == (v1 >= v2)

nipype/external/version.py

@@ -12,6 +12,8 @@
 # 2022.04.27 - Minor changes are made to the comments,
 #            - The StrictVersion class was removed
 #            - Black styling was applied
+# 2022.05.11 - Refactor LooseVersion._cmp to permit comparisons with
+#              distutils.version.LooseVersion
 #
 
 # distutils/version.py
@@ -38,6 +40,7 @@
     of the same class, thus must follow the same rules)
 """
 
+import sys
 import re
 
 
@@ -211,14 +214,27 @@ def __repr__(self):
         return "LooseVersion ('%s')" % str(self)
 
     def _cmp(self, other):
-        if isinstance(other, str):
-            other = LooseVersion(other)
-        elif not isinstance(other, LooseVersion):
-            return NotImplemented
+        other = self._coerce(other)
 
         if self.version == other.version:
             return 0
         if self.version < other.version:
             return -1
         if self.version > other.version:
             return 1
+
+    @staticmethod
+    def _coerce(other):
+        if isinstance(other, LooseVersion):
+            return other
+        elif isinstance(other, str):
+            return LooseVersion(other)
+        elif "distutils" in sys.modules:
+            # Using this check to avoid importing distutils and suppressing the warning
+            try:
+                from distutils.version import LooseVersion as deprecated
+            except ImportError:
+                return NotImplemented
+            if isinstance(other, deprecated):
+                return LooseVersion(str(other))
+        return NotImplemented