skip tests that use tracemalloc if not available

Author: mattip

pandas/tests/libs/test_hashtable.py

@@ -2,7 +2,10 @@
 from contextlib import contextmanager
 import re
 import struct
-import tracemalloc
+try:
+    import tracemalloc
+except ModuleNotFoundError:
+    tracemalloc = None
 
 import numpy as np
 import pytest
@@ -16,6 +19,8 @@
 
 @contextmanager
 def activated_tracemalloc() -> Generator[None, None, None]:
+    if not tracemalloc:
+        pytest.skip("no tracemalloc available")
     tracemalloc.start()
     try:
         yield