tbl: add _Column._index

Steve Canny · Steve Canny · commit 0e3e2be51edd · 2014-11-28T21:45:42.000-05:00
diff --git a/docx/oxml/table.py b/docx/oxml/table.py
@@ -97,6 +97,14 @@ class CT_TblGridCol(BaseOxmlElement):
     """
     w = OptionalAttribute('w:w', ST_TwipsMeasure)
 
+    @property
+    def gridCol_idx(self):
+        """
+        The index of this ``<w:gridCol>`` element within its parent
+        ``<w:tblGrid>`` element.
+        """
+        return self.getparent().gridCol_lst.index(self)
+
 
 class CT_TblLayoutType(BaseOxmlElement):
     """
diff --git a/docx/table.py b/docx/table.py
@@ -274,7 +274,7 @@ def _index(self):
         """
         Index of this column in its table, starting from zero.
         """
-        raise NotImplementedError
+        return self._gridCol.gridCol_idx
 
 
 class _ColumnCells(Parented):
diff --git a/tests/test_table.py b/tests/test_table.py
@@ -394,6 +394,10 @@ def it_can_change_its_width(self, width_set_fixture):
         assert column.width == value
         assert column._gridCol.xml == expected_xml
 
+    def it_knows_its_index_in_table_to_help(self, index_fixture):
+        column, expected_idx = index_fixture
+        assert column._index == expected_idx
+
     # fixtures -------------------------------------------------------
 
     @pytest.fixture
@@ -404,6 +408,13 @@ def cells_fixture(self, _index_, table_prop_, table_):
         table_.column_cells.return_value = list(expected_cells)
         return column, column_idx, expected_cells
 
+    @pytest.fixture
+    def index_fixture(self):
+        tbl = element('w:tbl/w:tblGrid/(w:gridCol,w:gridCol,w:gridCol)')
+        gridCol, expected_idx = tbl.tblGrid[1], 1
+        column = _Column(gridCol, tbl, None)
+        return column, expected_idx
+
     @pytest.fixture
     def table_fixture(self, parent_, table_):
         column = _Column(None, None, parent_)
