MAINT: Drop has_index_names input from read_excel (#16522)

doc/source/io.rst

@@ -2739,11 +2739,6 @@ should be passed to ``index_col`` and ``header``
    import os
    os.remove('path_to_file.xlsx')
 
-.. warning::
-
-   Excel files saved in version 0.16.2 or prior that had index names will still able to be read in,
-   but the ``has_index_names`` argument must specified to ``True``.
-
 
 Parsing Specific Columns
 ++++++++++++++++++++++++

doc/source/whatsnew/v0.21.0.txt

@@ -70,6 +70,7 @@ Deprecations
 Removal of prior version deprecations/changes
 ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
 
+- ``pd.read_excel()`` has dropped the ``has_index_names`` parameter (:issue:`10967`)
 
 
 .. _whatsnew_0210.performance:

pandas/io/excel.py

@@ -141,10 +141,6 @@
     convert integral floats to int (i.e., 1.0 --> 1). If False, all numeric
     data will be read in as floats: Excel stores all numbers as floats
     internally
-has_index_names : boolean, default None
-    DEPRECATED: for version 0.17+ index names will be automatically
-    inferred based on index_col.  To read Excel output from 0.16.2 and
-    prior that had saved index names, use True.
 
 Returns
 -------
@@ -198,8 +194,8 @@ def get_writer(engine_name):
 def read_excel(io, sheet_name=0, header=0, skiprows=None, skip_footer=0,
                index_col=None, names=None, parse_cols=None, parse_dates=False,
                date_parser=None, na_values=None, thousands=None,
-               convert_float=True, has_index_names=None, converters=None,
-               dtype=None, true_values=None, false_values=None, engine=None,
+               convert_float=True, converters=None, dtype=None,
+               true_values=None, false_values=None, engine=None,
                squeeze=False, **kwds):
 
     # Can't use _deprecate_kwarg since sheetname=None has a special meaning
@@ -218,10 +214,9 @@ def read_excel(io, sheet_name=0, header=0, skiprows=None, skip_footer=0,
         sheetname=sheet_name, header=header, skiprows=skiprows, names=names,
         index_col=index_col, parse_cols=parse_cols, parse_dates=parse_dates,
         date_parser=date_parser, na_values=na_values, thousands=thousands,
-        convert_float=convert_float, has_index_names=has_index_names,
-        skip_footer=skip_footer, converters=converters, dtype=dtype,
-        true_values=true_values, false_values=false_values, squeeze=squeeze,
-        **kwds)
+        convert_float=convert_float, skip_footer=skip_footer,
+        converters=converters, dtype=dtype, true_values=true_values,
+        false_values=false_values, squeeze=squeeze, **kwds)
 
 
 class ExcelFile(object):
@@ -283,9 +278,8 @@ def __fspath__(self):
     def parse(self, sheet_name=0, header=0, skiprows=None, skip_footer=0,
               names=None, index_col=None, parse_cols=None, parse_dates=False,
               date_parser=None, na_values=None, thousands=None,
-              convert_float=True, has_index_names=None,
-              converters=None, true_values=None, false_values=None,
-              squeeze=False, **kwds):
+              convert_float=True, converters=None, true_values=None,
+              false_values=None, squeeze=False, **kwds):
         """
         Parse specified sheet(s) into a DataFrame
 
@@ -296,7 +290,6 @@ def parse(self, sheet_name=0, header=0, skiprows=None, skip_footer=0,
         return self._parse_excel(sheetname=sheet_name, header=header,
                                  skiprows=skiprows, names=names,
                                  index_col=index_col,
-                                 has_index_names=has_index_names,
                                  parse_cols=parse_cols,
                                  parse_dates=parse_dates,
                                  date_parser=date_parser, na_values=na_values,
@@ -343,23 +336,17 @@ def _excel2num(x):
             return i in parse_cols
 
     def _parse_excel(self, sheetname=0, header=0, skiprows=None, names=None,
-                     skip_footer=0, index_col=None, has_index_names=None,
-                     parse_cols=None, parse_dates=False, date_parser=None,
-                     na_values=None, thousands=None, convert_float=True,
-                     true_values=None, false_values=None, verbose=False,
-                     dtype=None, squeeze=False, **kwds):
+                     skip_footer=0, index_col=None, parse_cols=None,
+                     parse_dates=False, date_parser=None, na_values=None,
+                     thousands=None, convert_float=True, true_values=None,
+                     false_values=None, verbose=False, dtype=None,
+                     squeeze=False, **kwds):
 
         skipfooter = kwds.pop('skipfooter', None)
         if skipfooter is not None:
             skip_footer = skipfooter
 
         _validate_header_arg(header)
-        if has_index_names is not None:
-            warn("\nThe has_index_names argument is deprecated; index names "
-                 "will be automatically inferred based on index_col.\n"
-                 "This argmument is still necessary if reading Excel output "
-                 "from 0.16.2 or prior with index names.", FutureWarning,
-                 stacklevel=3)
 
         if 'chunksize' in kwds:
             raise NotImplementedError("chunksize keyword of read_excel "
@@ -511,8 +498,7 @@ def _parse_cell(cell_contents, cell_typ):
                         else:
                             last = data[row][col]
 
-            if is_list_like(header) and len(header) > 1:
-                has_index_names = True
+            has_index_names = is_list_like(header) and len(header) > 1
 
             # GH 12292 : error when read one empty column from excel file
             try:

pandas/tests/io/test_excel.py

@@ -881,8 +881,42 @@ def test_excel_multindex_roundtrip(self):
                             tm.assert_frame_equal(
                                 df, act, check_names=check_names)
 
-    def test_excel_oldindex_format(self):
-        # GH 4679
+    def test_excel_old_index_format(self):
+        # see gh-4679
+        filename = 'test_index_name_pre17' + self.ext
+        in_file = os.path.join(self.dirpath, filename)
+
+        # We detect headers to determine if index names exist, so
+        # that "index" name in the "names" version of the data will
+        # now be interpreted as rows that include null data.
+        data = np.array([[None, None, None, None, None],
+                         ['R0C0', 'R0C1', 'R0C2', 'R0C3', 'R0C4'],
+                         ['R1C0', 'R1C1', 'R1C2', 'R1C3', 'R1C4'],
+                         ['R2C0', 'R2C1', 'R2C2', 'R2C3', 'R2C4'],
+                         ['R3C0', 'R3C1', 'R3C2', 'R3C3', 'R3C4'],
+                         ['R4C0', 'R4C1', 'R4C2', 'R4C3', 'R4C4']])
+        columns = ['C_l0_g0', 'C_l0_g1', 'C_l0_g2', 'C_l0_g3', 'C_l0_g4']
+        mi = MultiIndex(levels=[['R0', 'R_l0_g0', 'R_l0_g1',
+                                 'R_l0_g2', 'R_l0_g3', 'R_l0_g4'],
+                                ['R1', 'R_l1_g0', 'R_l1_g1',
+                                 'R_l1_g2', 'R_l1_g3', 'R_l1_g4']],
+                        labels=[[0, 1, 2, 3, 4, 5], [0, 1, 2, 3, 4, 5]],
+                        names=[None, None])
+        si = Index(['R0', 'R_l0_g0', 'R_l0_g1', 'R_l0_g2',
+                    'R_l0_g3', 'R_l0_g4'], name=None)
+
+        expected = pd.DataFrame(data, index=si, columns=columns)
+
+        actual = pd.read_excel(in_file, 'single_names')
+        tm.assert_frame_equal(actual, expected)
+
+        expected.index = mi
+
+        actual = pd.read_excel(in_file, 'multi_names')
+        tm.assert_frame_equal(actual, expected)
+
+        # The analogous versions of the "names" version data
+        # where there are explicitly no names for the indices.
         data = np.array([['R0C0', 'R0C1', 'R0C2', 'R0C3', 'R0C4'],
                          ['R1C0', 'R1C1', 'R1C2', 'R1C3', 'R1C4'],
                          ['R2C0', 'R2C1', 'R2C2', 'R2C3', 'R2C4'],
@@ -894,40 +928,19 @@ def test_excel_oldindex_format(self):
                                 ['R_l1_g0', 'R_l1_g1', 'R_l1_g2',
                                  'R_l1_g3', 'R_l1_g4']],
                         labels=[[0, 1, 2, 3, 4], [0, 1, 2, 3, 4]],
-                        names=['R0', 'R1'])
+                        names=[None, None])
         si = Index(['R_l0_g0', 'R_l0_g1', 'R_l0_g2',
-                    'R_l0_g3', 'R_l0_g4'], name='R0')
-
-        in_file = os.path.join(
-            self.dirpath, 'test_index_name_pre17' + self.ext)
+                    'R_l0_g3', 'R_l0_g4'], name=None)
 
         expected = pd.DataFrame(data, index=si, columns=columns)
-        with tm.assert_produces_warning(FutureWarning):
-            actual = pd.read_excel(
-                in_file, 'single_names', has_index_names=True)
-        tm.assert_frame_equal(actual, expected)
 
-        expected.index.name = None
         actual = pd.read_excel(in_file, 'single_no_names')
         tm.assert_frame_equal(actual, expected)
-        with tm.assert_produces_warning(FutureWarning):
-            actual = pd.read_excel(
-                in_file, 'single_no_names', has_index_names=False)
-        tm.assert_frame_equal(actual, expected)
 
         expected.index = mi
-        with tm.assert_produces_warning(FutureWarning):
-            actual = pd.read_excel(
-                in_file, 'multi_names', has_index_names=True)
-        tm.assert_frame_equal(actual, expected)
 
-        expected.index.names = [None, None]
         actual = pd.read_excel(in_file, 'multi_no_names', index_col=[0, 1])
         tm.assert_frame_equal(actual, expected, check_names=False)
-        with tm.assert_produces_warning(FutureWarning):
-            actual = pd.read_excel(in_file, 'multi_no_names', index_col=[0, 1],
-                                   has_index_names=False)
-        tm.assert_frame_equal(actual, expected, check_names=False)
 
     def test_read_excel_bool_header_arg(self):
         # GH 6114