Fixed typing_extensions being imported unconditionally on Python < 3.9

Fixes #217.
agronholm · Nov 22, 2021 · 4615f19 · 4615f19
1 parent 2516f18
commit 4615f19
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diff --git a/docs/versionhistory.rst b/docs/versionhistory.rst
@@ -3,6 +3,11 @@ Version history
 
 This library adheres to `Semantic Versioning 2.0 <https://semver.org/#semantic-versioning-200>`_.
 
+**2.13.2** (2021-11-23)
+
+- Fixed ``typing_extensions`` being imported unconditionally on Python < 3.9
+  (bug introduced in 2.13.1)
+
 **2.13.1** (2021-11-23)
 
 - Fixed ``@typechecked`` replacing abstract properties with regular properties

diff --git a/src/typeguard/__init__.py b/src/typeguard/__init__.py
@@ -69,10 +69,14 @@ def is_typeddict(tp) -> bool:
 
         return isinstance(tp, _TypedDictMeta)
 else:
-    def is_typeddict(tp) -> bool:
+    try:
         from typing_extensions import _TypedDictMeta
-
-        return isinstance(tp, _TypedDictMeta)
+    except ImportError:
+        def is_typeddict(tp) -> bool:
+            return False
+    else:
+        def is_typeddict(tp) -> bool:
+            return isinstance(tp, _TypedDictMeta)
 
 
 if TYPE_CHECKING: