Test xlsxwriter styling

Author: jnothman

doc/source/style.ipynb

@@ -918,7 +918,7 @@
     "\n",
     "<span style=\"color: red\">*Experimental: This is a new feature and still under development. We'll be adding features and possibly making breaking changes in future releases. We'd love to hear your feedback.*</span>\n",
     "\n",
-    "Some support is available for exporting styled `DataFrames` to Excel worksheets using the `OpenPyXL` engine. CSS2.2 properties handled include:\n",
+    "Some support is available for exporting styled `DataFrames` to Excel worksheets using the `OpenPyXL` or `xlsxwriter` engines. CSS2.2 properties handled include:\n",
     "\n",
     "- `background-color`\n",
     "- `border-style`, `border-width`, `border-color` and their {`top`, `right`, `bottom`, `left` variants}\n",

doc/source/whatsnew/v0.20.0.txt

@@ -368,7 +368,7 @@ To convert a ``SparseDataFrame`` back to sparse SciPy matrix in COO format, you
 Excel output for styled DataFrames
 ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
 
-Experimental support has been added to export ``DataFrame.style`` formats to Excel using the ``openpyxl`` engine. (:issue:`15530`)
+Experimental support has been added to export ``DataFrame.style`` formats to Excel using the ``openpyxl`` or ``xlsxwriter`` engines. (:issue:`15530`, :issue:`16149`)
 
 For example, after running the following, ``styled.xlsx`` renders as below:
 

pandas/io/excel.py

@@ -1602,6 +1602,7 @@ def write_cells(self, cells, sheet_name=None, startrow=0, startcol=0,
         (('font', 'sz'), 'font_size'),
         (('font', 'size'), 'font_size'),
         (('font', 'color', 'rgb'), 'font_color'),
+        (('font', 'color'), 'font_color'),
         (('font', 'b'), 'bold'),
         (('font', 'bold'), 'bold'),
         (('font', 'i'), 'italic'),

pandas/tests/io/test_excel.py

@@ -2408,85 +2408,93 @@ def custom_converter(css):
         styled.to_excel(writer, sheet_name='styled')
         ExcelFormatter(styled, style_converter=custom_converter).write(
             writer, sheet_name='custom')
+        writer.save()
 
-    # For engines other than openpyxl 2, we only smoke test
-    if engine != 'openpyxl':
-        return
-    if not openpyxl_compat.is_compat(major_ver=2):
-        pytest.skip('incompatible openpyxl version')
-
-    # (1) compare DataFrame.to_excel and Styler.to_excel when unstyled
-    n_cells = 0
-    for col1, col2 in zip(writer.sheets['frame'].columns,
-                          writer.sheets['unstyled'].columns):
-        assert len(col1) == len(col2)
-        for cell1, cell2 in zip(col1, col2):
-            assert cell1.value == cell2.value
-            assert_equal_style(cell1, cell2)
-            n_cells += 1
-
-    # ensure iteration actually happened:
-    assert n_cells == (10 + 1) * (3 + 1)
-
-    # (2) check styling with default converter
-    n_cells = 0
-    for col1, col2 in zip(writer.sheets['frame'].columns,
-                          writer.sheets['styled'].columns):
-        assert len(col1) == len(col2)
-        for cell1, cell2 in zip(col1, col2):
-            ref = '%s%d' % (cell2.column, cell2.row)
-            # XXX: this isn't as strong a test as ideal; we should
-            #      differences are exclusive
-            if ref == 'B2':
-                assert not cell1.font.bold
-                assert cell2.font.bold
-            elif ref == 'C3':
-                assert cell1.font.color.rgb != cell2.font.color.rgb
-                assert cell2.font.color.rgb == '000000FF'
-            elif ref == 'D4':
-                assert cell1.font.underline != cell2.font.underline
-                assert cell2.font.underline == 'single'
-            elif ref == 'B5':
-                assert not cell1.border.left.style
-                assert (cell2.border.top.style ==
-                        cell2.border.right.style ==
-                        cell2.border.bottom.style ==
-                        cell2.border.left.style ==
-                        'medium')
-            elif ref == 'C6':
-                assert not cell1.font.italic
-                assert cell2.font.italic
-            elif ref == 'D7':
-                assert (cell1.alignment.horizontal !=
-                        cell2.alignment.horizontal)
-                assert cell2.alignment.horizontal == 'right'
-            elif ref == 'B8':
-                assert cell1.fill.fgColor.rgb != cell2.fill.fgColor.rgb
-                assert cell1.fill.patternType != cell2.fill.patternType
-                assert cell2.fill.fgColor.rgb == '00FF0000'
-                assert cell2.fill.patternType == 'solid'
-            else:
-                assert_equal_style(cell1, cell2)
-
-            assert cell1.value == cell2.value
-            n_cells += 1
-
-    assert n_cells == (10 + 1) * (3 + 1)
-
-    # (3) check styling with custom converter
-    n_cells = 0
-    for col1, col2 in zip(writer.sheets['frame'].columns,
-                          writer.sheets['custom'].columns):
-        assert len(col1) == len(col2)
-        for cell1, cell2 in zip(col1, col2):
-            ref = '%s%d' % (cell2.column, cell2.row)
-            if ref in ('B2', 'C3', 'D4', 'B5', 'C6', 'D7', 'B8'):
-                assert not cell1.font.bold
-                assert cell2.font.bold
-            else:
-                assert_equal_style(cell1, cell2)
+        if engine not in ('openpyxl', 'xlsxwriter'):
+            # For other engines, we only smoke test
+            return
+        openpyxl = pytest.importorskip('openpyxl')
+        if not openpyxl_compat.is_compat(major_ver=2):
+            pytest.skip('incompatible openpyxl version')
 
-            assert cell1.value == cell2.value
-            n_cells += 1
+        wb = openpyxl.load_workbook(path)
 
-    assert n_cells == (10 + 1) * (3 + 1)
+        # (1) compare DataFrame.to_excel and Styler.to_excel when unstyled
+        n_cells = 0
+        for col1, col2 in zip(wb['frame'].columns,
+                              wb['unstyled'].columns):
+            assert len(col1) == len(col2)
+            for cell1, cell2 in zip(col1, col2):
+                assert cell1.value == cell2.value
+                assert_equal_style(cell1, cell2)
+                n_cells += 1
+
+        # ensure iteration actually happened:
+        assert n_cells == (10 + 1) * (3 + 1)
+
+        # (2) check styling with default converter
+
+        # XXX: openpyxl (as at 2.4) prefixes colors with 00, xlsxwriter with FF
+        alpha = '00' if engine == 'openpyxl' else 'FF'
+
+        n_cells = 0
+        for col1, col2 in zip(wb['frame'].columns,
+                              wb['styled'].columns):
+            assert len(col1) == len(col2)
+            for cell1, cell2 in zip(col1, col2):
+                ref = '%s%d' % (cell2.column, cell2.row)
+                # XXX: this isn't as strong a test as ideal; we should
+                #      confirm that differences are exclusive
+                if ref == 'B2':
+                    assert not cell1.font.bold
+                    assert cell2.font.bold
+                elif ref == 'C3':
+                    assert cell1.font.color.rgb != cell2.font.color.rgb
+                    assert cell2.font.color.rgb == alpha + '0000FF'
+                elif ref == 'D4':
+                    assert cell1.font.underline != cell2.font.underline
+                    assert cell2.font.underline == 'single'
+                elif ref == 'B5':
+                    assert not cell1.border.left.style
+                    assert (cell2.border.top.style ==
+                            cell2.border.right.style ==
+                            cell2.border.bottom.style ==
+                            cell2.border.left.style ==
+                            'medium')
+                elif ref == 'C6':
+                    assert not cell1.font.italic
+                    assert cell2.font.italic
+                elif ref == 'D7':
+                    assert (cell1.alignment.horizontal !=
+                            cell2.alignment.horizontal)
+                    assert cell2.alignment.horizontal == 'right'
+                elif ref == 'B8':
+                    assert cell1.fill.fgColor.rgb != cell2.fill.fgColor.rgb
+                    assert cell1.fill.patternType != cell2.fill.patternType
+                    assert cell2.fill.fgColor.rgb == alpha + 'FF0000'
+                    assert cell2.fill.patternType == 'solid'
+                else:
+                    assert_equal_style(cell1, cell2)
+
+                assert cell1.value == cell2.value
+                n_cells += 1
+
+        assert n_cells == (10 + 1) * (3 + 1)
+
+        # (3) check styling with custom converter
+        n_cells = 0
+        for col1, col2 in zip(wb['frame'].columns,
+                              wb['custom'].columns):
+            assert len(col1) == len(col2)
+            for cell1, cell2 in zip(col1, col2):
+                ref = '%s%d' % (cell2.column, cell2.row)
+                if ref in ('B2', 'C3', 'D4', 'B5', 'C6', 'D7', 'B8'):
+                    assert not cell1.font.bold
+                    assert cell2.font.bold
+                else:
+                    assert_equal_style(cell1, cell2)
+
+                assert cell1.value == cell2.value
+                n_cells += 1
+
+        assert n_cells == (10 + 1) * (3 + 1)