Cleaned up code and tests

- Minor edit to whatsnew entry to use Timedelta and the class tag
- Moved test comments inside functions
- Cleaned up tests to make them less verbose
- Changed timedelta conversion in test and write_cells to use timedelta.total_seconds()
- In write_cells, changed timedelta if to elif
- Removed Period import that was no longer used due to refactoring of _conv_value

Author: cbertinato

doc/source/whatsnew/v0.23.0.txt

@@ -489,8 +489,8 @@ I/O
 - Bug in :func:`DataFrame.to_latex()` where pairs of braces meant to serve as invisible placeholders were escaped (:issue:`18667`)
 - Bug in :func:`read_json` where large numeric values were causing an ``OverflowError`` (:issue:`18842`)
 - Bug in :func:`DataFrame.to_parquet` where an exception was raised if the write destination is S3 (:issue:`19134`)
-- Type ``Interval`` now supported in :func:`DataFrame.to_excel` for all Excel file types (:issue:`19242`)
-- Type ``timedelta`` now supported in :func:`DataFrame.to_excel` for xls file type (:issue:`19242`, :issue:`9155`)
+- :class:`Interval` now supported in :func:`DataFrame.to_excel` for all Excel file types (:issue:`19242`)
+- :class:`Timedelta` now supported in :func:`DataFrame.to_excel` for xls file type (:issue:`19242`, :issue:`9155`)
 -
 
 Plotting

pandas/io/excel.py

@@ -21,7 +21,6 @@
 from pandas.io.common import (_is_url, _urlopen, _validate_header_arg,
                               get_filepath_or_buffer, _NA_VALUES,
                               _stringify_path)
-# from pandas.core.indexes.period import Period
 import pandas._libs.json as json
 from pandas.compat import (map, zip, reduce, range, lrange, u, add_metaclass,
                            string_types, OrderedDict)
@@ -1463,12 +1462,9 @@ def write_cells(self, cells, sheet_name=None, startrow=0, startcol=0,
                 num_format_str = self.datetime_format
             elif isinstance(cell.val, date):
                 num_format_str = self.date_format
-
-            if isinstance(cell.val, timedelta):
+            elif isinstance(cell.val, timedelta):
                 delta = cell.val
-                val = (delta.days + (float(delta.seconds) +
-                                     float(delta.microseconds) / 1E6) /
-                       (60 * 60 * 24))
+                val = delta.total_seconds() / float(86400)
 
             stylekey = json.dumps(cell.style)
             if num_format_str:

pandas/tests/io/test_excel.py

@@ -1440,61 +1440,51 @@ def test_excel_date_datetime_format(self):
                 # to use df_expected to check the result
                 tm.assert_frame_equal(rs2, df_expected)
 
-    # GH19242 - test writing Interval without labels
-    def test_to_excel_interval_no_label(self):
+    def test_to_excel_interval_no_labels(self):
+        # GH19242 - test writing Interval without labels
         _skip_if_no_xlrd()
 
         with ensure_clean(self.ext) as path:
-            rand = np.random.randint(-10, 10, size=(20, 2))
-            frame = DataFrame(rand)
-            intervals = pd.cut(frame[0], 10)
-            frame['new'] = intervals
-            frame_expected = DataFrame(rand)
-            frame_expected['new'] = intervals.astype(str)
+            frame = DataFrame(np.random.randint(-10, 10, size=(20, 1)))
+            expected = frame.copy()
+            frame['new'] = pd.cut(frame[0], 10)
+            expected['new'] = pd.cut(expected[0], 10).astype(str)
             frame.to_excel(path, 'test1')
             reader = ExcelFile(path)
             recons = read_excel(reader, 'test1')
-            tm.assert_frame_equal(frame_expected, recons)
+            tm.assert_frame_equal(expected, recons)
 
-    # GH19242 - test writing Interval with labels
-    def test_to_excel_interval_w_label(self):
+    def test_to_excel_interval_labels(self):
+        # GH19242 - test writing Interval with labels
         _skip_if_no_xlrd()
 
         with ensure_clean(self.ext) as path:
-            rand = np.random.randint(-10, 10, size=(20, 2))
-            frame = DataFrame(rand)
+            frame = DataFrame(np.random.randint(-10, 10, size=(20, 1)))
+            expected = frame.copy()
             intervals = pd.cut(frame[0], 10, labels=['A', 'B', 'C', 'D', 'E',
                                                      'F', 'G', 'H', 'I', 'J'])
             frame['new'] = intervals
-            frame_expected = DataFrame(rand)
-            frame_expected['new'] = pd.Series(list(intervals))
+            expected['new'] = pd.Series(list(intervals))
             frame.to_excel(path, 'test1')
             reader = ExcelFile(path)
             recons = read_excel(reader, 'test1')
-            tm.assert_frame_equal(frame_expected, recons)
+            tm.assert_frame_equal(expected, recons)
 
-    # GH 19242 & GH9155 - test writing timedelta to xls
     def test_to_excel_timedelta(self):
+        # GH 19242, GH9155 - test writing timedelta to xls
         _skip_if_no_xlrd()
 
         with ensure_clean('.xls') as path:
-            rand = np.random.randint(-10, 10, size=(20, 1))
-            frame = DataFrame(rand, columns=['A'])
+            frame = DataFrame(np.random.randint(-10, 10, size=(20, 1)),
+                              columns=['A'])
+            expected = frame.copy()
             frame['new'] = frame['A'].apply(lambda x: timedelta(seconds=x))
-            frame_expected = DataFrame(rand, columns=['A'])
-            delta = frame_expected['A'].apply(lambda x: timedelta(seconds=x))
-
-            def timedelta_rep(x):
-                return (x.days + (float(x.seconds) +
-                                  float(x.microseconds) / 1E6) /
-                        (60 * 60 * 24))
-
-            frame_expected['new'] = delta.apply(timedelta_rep)
+            expected['new'] = expected['A'].apply(
+                lambda x: timedelta(seconds=x).total_seconds() / float(86400))
             frame.to_excel(path, 'test1')
             reader = ExcelFile(path)
             recons = read_excel(reader, 'test1')
-
-            tm.assert_frame_equal(frame_expected, recons)
+            tm.assert_frame_equal(expected, recons)
 
     def test_to_excel_periodindex(self):
         _skip_if_no_xlrd()