detect beginning of new row. if last row is incomplete, add empty cells.

docx/table.py

@@ -168,6 +168,11 @@ def _cells(self):
         col_count = self._column_count
         cells = []
         for tc in self._tbl.iter_tcs():
+            previousRowIncomplete = (tc.left == 0) and (len(cells) % col_count > 0)
+            if previousRowIncomplete:
+                missingCellCount = col_count - (len(cells) % col_count)
+                for i in range(0, missingCellCount):
+                    cells.append(_Cell("w:tc", self))
             for grid_span_idx in range(tc.grid_span):
                 if tc.vMerge == ST_Merge.CONTINUE:
                     cells.append(cells[-col_count])

tests/test_table.py

@@ -69,6 +69,11 @@ def it_provides_access_to_the_cells_in_a_row(self, row_cells_fixture):
         row_cells = table.row_cells(row_idx)
         assert row_cells == expected_cells
 
+    def it_detects_the_beginning_of_new_rows(self, inconsistet_col_span_fixture):
+        table, row_idx, col_idx, expected_text = inconsistet_col_span_fixture
+        cell = table.cell(row_idx, col_idx)
+        assert cell.text == expected_text
+
     def it_knows_its_alignment_setting(self, alignment_get_fixture):
         table, expected_value = alignment_get_fixture
         assert table.alignment == expected_value
@@ -269,6 +274,20 @@ def row_cells_fixture(self, _cells_, _column_count_):
         expected_cells = [3, 4, 5]
         return table, row_idx, expected_cells
 
+    @pytest.fixture
+    def inconsistet_col_span_fixture(self):
+        # the second row is missing one column
+        tbl_cxml = 'w:tbl/(w:tblGrid/(w:gridCol,w:gridCol,w:gridCol)' \
+            + ',w:tr/(w:tc,w:tc/w:tcPr/w:gridSpan{w:val=2})' \
+            + ',w:tr/(w:tc,w:tc/w:tcPr/w:gridSpan{w:val=1})' \
+            + ',w:tr/(w:tc/w:p/w:r/w:t"correct cell",w:tc/w:tcPr/w:gridSpan{w:val=2})' \
+            + ')'
+        table = Table(element(tbl_cxml), None)
+        row_idx = 2
+        col_idx = 0
+        expected_text = "correct cell"
+        return table, row_idx, col_idx, expected_text
+
     @pytest.fixture
     def style_get_fixture(self, part_prop_):
         style_id = 'Barbaz'