BUG: unclosed file handle in mmap

Author: jbrockmendel

pandas/io/common.py

@@ -535,6 +535,8 @@ def get_handle(
         try:
             wrapped = _MMapWrapper(f)
             f.close()
+            handles.remove(f)
+            handles.append(wrapped)
             f = wrapped
         except Exception:
             # we catch any errors that may have occurred