Backport PR pandas-dev#24965: Fixed itertuples usage in to_dict

doc/source/whatsnew/v0.24.1.rst

@@ -15,6 +15,13 @@ Whats New in 0.24.1 (February XX, 2019)
 These are the changes in pandas 0.24.1. See :ref:`release` for a full changelog
 including other versions of pandas.
 
+.. _whatsnew_0241.regressions:
+
+Fixed Regressions
+^^^^^^^^^^^^^^^^^
+
+- Bug in :meth:`DataFrame.itertuples` with ``records`` orient raising an ``AttributeError`` when the ``DataFrame`` contained more than 255 columns (:issue:`24939`)
+- Bug in :meth:`DataFrame.itertuples` orient converting integer column names to strings prepended with an underscore (:issue:`24940`)
 
 .. _whatsnew_0241.enhancements:
 

pandas/core/frame.py

@@ -847,7 +847,7 @@ def itertuples(self, index=True, name="Pandas"):
         ----------
         index : bool, default True
             If True, return the index as the first element of the tuple.
-        name : str, default "Pandas"
+        name : str or None, default "Pandas"
             The name of the returned namedtuples or None to return regular
             tuples.
 
@@ -1290,23 +1290,26 @@ def to_dict(self, orient='dict', into=dict):
                            ('columns', self.columns.tolist()),
                            ('data', [
                                list(map(com.maybe_box_datetimelike, t))
-                               for t in self.itertuples(index=False)]
-                            )))
+                               for t in self.itertuples(index=False, name=None)
+                           ])))
         elif orient.lower().startswith('s'):
             return into_c((k, com.maybe_box_datetimelike(v))
                           for k, v in compat.iteritems(self))
         elif orient.lower().startswith('r'):
+            columns = self.columns.tolist()
+            rows = (dict(zip(columns, row))
+                    for row in self.itertuples(index=False, name=None))
             return [
                 into_c((k, com.maybe_box_datetimelike(v))
-                       for k, v in compat.iteritems(row._asdict()))
-                for row in self.itertuples(index=False)]
+                       for k, v in compat.iteritems(row))
+                for row in rows]
         elif orient.lower().startswith('i'):
             if not self.index.is_unique:
                 raise ValueError(
                     "DataFrame index must be unique for orient='index'."
                 )
             return into_c((t[0], dict(zip(self.columns, t[1:])))
-                          for t in self.itertuples())
+                          for t in self.itertuples(name=None))
         else:
             raise ValueError("orient '{o}' not understood".format(o=orient))
 

pandas/tests/frame/test_convert_to.py

@@ -488,3 +488,17 @@ def test_to_dict_index_dtypes(self, into, expected):
         result = DataFrame.from_dict(result, orient='index')[cols]
         expected = DataFrame.from_dict(expected, orient='index')[cols]
         tm.assert_frame_equal(result, expected)
+
+    def test_to_dict_numeric_names(self):
+        # https://github.com/pandas-dev/pandas/issues/24940
+        df = DataFrame({str(i): [i] for i in range(5)})
+        result = set(df.to_dict('records')[0].keys())
+        expected = set(df.columns)
+        assert result == expected
+
+    def test_to_dict_wide(self):
+        # https://github.com/pandas-dev/pandas/issues/24939
+        df = DataFrame({('A_{:d}'.format(i)): [i] for i in range(256)})
+        result = df.to_dict('records')[0]
+        expected = {'A_{:d}'.format(i): i for i in range(256)}
+        assert result == expected