Something that might work.

src/idpyoidc/storage/listfile.py

@@ -40,17 +40,14 @@ def get_mtime(fname):
         :param fname: File name
         :return: The last time the file was modified.
         """
+        p = Path(fname)
         try:
-            target = Path(fname)
-            mtime = target.stat().st_mtime
-            # mtime = os.stat(fname).st_mtime_ns
+            mtime = p.stat().st_mtime
         except OSError:
-            # The file might be right in the middle of being written to
+            # The file might be right in the middle of being created
             # so sleep
             time.sleep(1)
-            target = Path(fname)
-            mtime = target.stat().st_mtime
-            # mtime = os.stat(fname).st_mtime_ns
+            mtime = p.stat().st_mtime
 
         return mtime
 

tests/test_14_read_only_list_file.py

@@ -1,4 +1,5 @@
 import os
+from time import sleep
 
 from idpyoidc.storage.listfile import ReadOnlyListFile
 
@@ -22,6 +23,7 @@ def test_read_only_list_file():
         for line in ["one", "two", "three"]:
             fp.write(line + '\n')
 
+    sleep(1)
     assert len(_read_only) == 3
     assert set(_read_only) == {"one", "two", "three"}
     assert _read_only[-1] == "three"