Track new handles in _get_handle

#14576 (comment)
#14576 (comment)

Author: dhimmel

pandas/formats/format.py

@@ -1455,7 +1455,7 @@ def save(self):
             f = self.path_or_buf
             close = False
         else:
-            f = _get_handle(self.path_or_buf, self.mode,
+            f, new_handle = _get_handle(self.path_or_buf, self.mode,
                             encoding=self.encoding,
                             compression=self.compression)
             close = True

pandas/io/common.py

@@ -295,9 +295,14 @@ def _get_handle(path_or_buf, mode, encoding=None, compression=None,
 
     Returns
     -------
-    A file like object.
+    f : file-like
+        A file-like object
+    new_handle : file-like or None
+        A file-like object that was openned in this function. Or None if none
+        were openned.
     """
 
+    new_handle = None
     f = path_or_buf
     is_path = isinstance(path_or_buf, compat.string_types)
 
@@ -358,7 +363,8 @@ def _get_handle(path_or_buf, mode, encoding=None, compression=None,
             from io import TextIOWrapper
             f = TextIOWrapper(f, encoding=encoding)
 
-        return f
+        new_handle = f
+        return f, new_handle
 
     elif is_path:
         if compat.PY2:
@@ -370,11 +376,13 @@ def _get_handle(path_or_buf, mode, encoding=None, compression=None,
         else:
             # Python 3 and no explicit encoding
             f = open(path_or_buf, mode, errors='replace')
+        new_handle = f
 
     # in Python 3, convert BytesIO or fileobjects passed with an encoding
     if compat.PY3 and isinstance(path_or_buf, compat.BytesIO):
         from io import TextIOWrapper
         f = TextIOWrapper(f, encoding=encoding)
+        new_handle = f
 
     if memory_map and hasattr(f, 'fileno'):
         try:
@@ -388,7 +396,7 @@ def _get_handle(path_or_buf, mode, encoding=None, compression=None,
             # leave the file handler as is then
             pass
 
-    return f
+    return f, new_handle
 
 
 class MMapWrapper(BaseIterator):

pandas/io/json.py

@@ -259,8 +259,10 @@ def read_json(path_or_buf=None, orient=None, typ='frame', dtype=True,
             exists = False
 
         if exists:
-            with _get_handle(filepath_or_buffer, 'r', encoding=encoding) as fh:
-                json = fh.read()
+            fh, new_handle = _get_handle(filepath_or_buffer, 'r',
+                                         encoding=encoding)
+            json = fh.read()
+            fh.close()
         else:
             json = filepath_or_buffer
     elif hasattr(filepath_or_buffer, 'read'):

pandas/io/parsers.py

@@ -1805,18 +1805,11 @@ def __init__(self, f, **kwds):
         self.comment = kwds['comment']
         self._comment_lines = []
 
-        add_handle = (
-            isinstance(f, compat.string_types) or
-            self.compression or
-            (compat.PY3 and isinstance(f, compat.BytesIO))
-        )
-
-        f = _get_handle(f, 'r', encoding=self.encoding,
-                        compression=self.compression,
-                        memory_map=self.memory_map)
-
-        if add_handle:
-            self.handles.append(f)
+        f, new_handle = _get_handle(f, 'r', encoding=self.encoding,
+                                    compression=self.compression,
+                                    memory_map=self.memory_map)
+        if new_handle is not None:
+            self.handles.append(new_handle)
 
         # Set self.data to something that can read lines.
         if hasattr(f, 'readline'):