df.from_records should accept values deriving from ABC collections.Mapping #3000

doc/source/v0.11.0.txt

@@ -280,6 +280,10 @@ Enhancements
   - value_counts() now accepts a "normalize" argument, for normalized
     histograms. (GH2710_).
 
+  - DataFrame.from_records now accepts not only dicts but any instance of
+    the collections.Mapping ABC.
+
+
 
 Bug Fixes
 ~~~~~~~~~

pandas/core/frame.py

@@ -17,6 +17,7 @@
 import csv
 import operator
 import sys
+import collections
 
 from numpy import nan as NA
 import numpy as np
@@ -413,7 +414,7 @@ def __init__(self, data=None, index=None, columns=None, dtype=None,
                 if index is None and isinstance(data[0], Series):
                     index = _get_names_from_index(data)
 
-                if isinstance(data[0], (list, tuple, dict, Series)):
+                if isinstance(data[0], (list, tuple, collections.Mapping, Series)):
                     arrays, columns = _to_arrays(data, columns, dtype=dtype)
                     columns = _ensure_index(columns)
 
@@ -5527,7 +5528,7 @@ def _to_arrays(data, columns, coerce_float=False, dtype=None):
     if isinstance(data[0], (list, tuple)):
         return _list_to_arrays(data, columns, coerce_float=coerce_float,
                                dtype=dtype)
-    elif isinstance(data[0], dict):
+    elif isinstance(data[0], collections.Mapping):
         return _list_of_dict_to_arrays(data, columns,
                                        coerce_float=coerce_float,
                                        dtype=dtype)

pandas/tests/test_frame.py

@@ -3246,6 +3246,22 @@ def test_to_records_dt64(self):
         rs = df.to_records(convert_datetime64=False)
         self.assert_(rs['index'][0] == df.index.values[0])
 
+    def test_to_records_with_Mapping_type(self):
+        import email
+        from email.parser import Parser
+        import collections
+
+        collections.Mapping.register(email.message.Message)
+
+        headers = Parser().parsestr('From: <user@example.com>\n'
+                'To: <someone_else@example.com>\n'
+                'Subject: Test message\n'
+                '\n'
+                'Body would go here\n')
+
+        frame = DataFrame.from_records([headers])
+        all( x in frame for x in ['Type','Subject','From'])
+
     def test_from_records_to_records(self):
         # from numpy documentation
         arr = np.zeros((2,), dtype=('i4,f4,a10'))