Merge pull request #90 from SwayamInSync/workaround-cpython-149728-lazyimport-race

Pre-import numpy lazy submodules before running tests

Author: SwayamInSync

tests/conftest.py

@@ -0,0 +1,15 @@
+# Pre-import numpy's lazy submodules in single-threaded context before
+# pytest-run-parallel forks workers. Works around CPython issue https://github.com/python/cpython/issues/149728 
+# which causes numpy's lazy __getattr__ on rec/ma/linalg/fft/... to recurse
+# to RecursionError under concurrent first-touch from multiple threads.
+# Drop this file when CPython bugfix release happens.
+
+import numpy
+
+for _attr in (
+    "linalg", "fft", "dtypes", "random", "polynomial", "ma",
+    "ctypeslib", "exceptions", "testing", "matlib", "f2py",
+    "typing", "rec", "char", "core", "strings",
+):
+    getattr(numpy, _attr)
+del _attr