Respect padding in pipe/github separator rows

Follow up on #410; Refs #260 and #261.

Author: kdeldycke

README.md

@@ -238,7 +238,7 @@ corresponds to the `pipe` format with the same alignment colons:
 ```pycon
 >>> print(tabulate(table, headers, tablefmt="github"))
 | item   |   qty |
-|:-------|------:|
+| :----- | ----: |
 | spam   |    42 |
 | eggs   |   451 |
 | bacon  |     0 |
@@ -487,7 +487,7 @@ indicate column alignment:
 ```pycon
 >>> print(tabulate(table, headers, tablefmt="pipe"))
 | item   |   qty |
-|:-------|------:|
+| :----- | ----: |
 | spam   |    42 |
 | eggs   |   451 |
 | bacon  |     0 |
@@ -931,7 +931,7 @@ spam
 >>> print(tabulate(table, headers, tablefmt="pipe"))
 | item   |   qty |
 | name   |       |
-|:-------|------:|
+| :----- | ----: |
 | eggs   |   451 |
 | more   |    42 |
 | spam   |       |

tabulate/__init__.py

@@ -131,26 +131,37 @@ def _is_separating_line(row):
     )
 
 
-def _pipe_segment_with_colons(align, colwidth):
+def _pipe_segment_with_colons(align, colwidth, padding=0):
     """Return a segment of a horizontal line with optional colons which
-    indicate column's alignment (as in `pipe` output format)."""
+    indicate column's alignment (as in `pipe` output format).
+
+    When ``padding`` is non-zero, the segment respects the format's padding by
+    placing spaces at the padding positions instead of filling the entire width
+    with dashes.  This makes separator rows consistent with data rows, which
+    already honour padding via ``_pad_row``.
+    """
     w = colwidth
+    pad = " " * padding
+    # Width available for dashes and alignment colons.
+    dw = w - 2 * padding
     if align in ["right", "decimal"]:
-        return ("-" * (w - 1)) + ":"
+        return pad + ("-" * (dw - 1)) + ":" + pad
     elif align == "center":
-        return ":" + ("-" * (w - 2)) + ":"
+        return pad + ":" + ("-" * (dw - 2)) + ":" + pad
     elif align == "left":
-        return ":" + ("-" * (w - 1))
+        return pad + ":" + ("-" * (dw - 1)) + pad
     else:
-        return "-" * w
+        return pad + ("-" * dw) + pad
 
 
-def _pipe_line_with_colons(colwidths, colaligns):
+def _pipe_line_with_colons(colwidths, colaligns, padding=0):
     """Return a horizontal line with optional colons to indicate column's
     alignment (as in `pipe` output format)."""
     if not colaligns:  # e.g. printing an empty data frame (github issue #15)
         colaligns = [""] * len(colwidths)
-    segments = "|".join(_pipe_segment_with_colons(a, w) for a, w in zip(colaligns, colwidths))
+    segments = "|".join(
+        _pipe_segment_with_colons(a, w, padding) for a, w in zip(colaligns, colwidths)
+    )
     return f"|{segments}|"
 
 
@@ -168,7 +179,7 @@ def _grid_segment_with_colons(colwidth, align):
         return "=" * width
 
 
-def _grid_line_with_colons(colwidths, colaligns):
+def _grid_line_with_colons(colwidths, colaligns, **kwargs):
     """Return a horizontal line with optional colons to indicate column's alignment
     in a grid table."""
     if not colaligns:
@@ -200,7 +211,7 @@ def _textile_row_with_attrs(cell_values, colwidths, colaligns):
     return f"|{values}|"
 
 
-def _html_begin_table_without_header(colwidths_ignore, colaligns_ignore):
+def _html_begin_table_without_header(colwidths_ignore, colaligns_ignore, **kwargs):
     # this table header will be suppressed if there is a header row
     return "<table>\n<tbody>"
 
@@ -242,7 +253,7 @@ def _moin_row_with_attrs(celltag, cell_values, colwidths, colaligns, header=""):
     return "".join(values_with_attrs) + "||"
 
 
-def _latex_line_begin_tabular(colwidths, colaligns, booktabs=False, longtable=False):
+def _latex_line_begin_tabular(colwidths, colaligns, booktabs=False, longtable=False, **kwargs):
     alignment = {"left": "l", "right": "r", "center": "c", "decimal": "r"}
     tabular_columns_fmt = "".join([alignment.get(a, "l") for a in colaligns])
     return "\n".join(
@@ -255,7 +266,7 @@ def _latex_line_begin_tabular(colwidths, colaligns, booktabs=False, longtable=Fa
     )
 
 
-def _asciidoc_row(is_header, *args):
+def _asciidoc_row(is_header, *args, **kwargs):
     """handle header and data rows for asciidoc format"""
 
     def make_header_line(is_header, colwidths, colaligns):
@@ -2063,7 +2074,7 @@ def tabulate(
     >>> print(tabulate([["spam", 41.9999], ["eggs", "451.0"]],
     ...                ["strings", "numbers"], "pipe"))
     | strings   |   numbers |
-    |:----------|----------:|
+    | :-------- | --------: |
     | spam      |   41.9999 |
     | eggs      |  451      |
 
@@ -2077,7 +2088,7 @@ def tabulate(
      eggs      |  451
 
     >>> print(tabulate([["spam", 41.9999], ["eggs", "451.0"]], tablefmt="pipe"))
-    |:-----|---------:|
+    | :--- | -------: |
     | spam |  41.9999 |
     | eggs | 451      |
 
@@ -2578,21 +2589,21 @@ def _append_multiline_row(
     return lines
 
 
-def _build_line(colwidths, colaligns, linefmt):
+def _build_line(colwidths, colaligns, linefmt, padding=0):
     "Return a string which represents a horizontal line."
     if not linefmt:
         return None
     if callable(linefmt):
-        return linefmt(colwidths, colaligns)
+        return linefmt(colwidths, colaligns, padding=padding)
     else:
         begin, fill, sep, end = linefmt
         cells = [fill * w for w in colwidths]
         rowfmt = DataRow(begin, sep, end)
         return _build_simple_row(cells, rowfmt)
 
 
-def _append_line(lines, colwidths, colaligns, linefmt):
-    lines.append(_build_line(colwidths, colaligns, linefmt))
+def _append_line(lines, colwidths, colaligns, linefmt, padding=0):
+    lines.append(_build_line(colwidths, colaligns, linefmt, padding=padding))
     return lines
 
 
@@ -2629,12 +2640,12 @@ def _format_table(
     padded_headers = pad_row(headers, pad)
 
     if fmt.lineabove and "lineabove" not in hidden:
-        _append_line(lines, padded_widths, colaligns, fmt.lineabove)
+        _append_line(lines, padded_widths, colaligns, fmt.lineabove, padding=pad)
 
     if padded_headers:
         append_row(lines, padded_headers, padded_widths, headersaligns, headerrow)
         if fmt.linebelowheader and "linebelowheader" not in hidden:
-            _append_line(lines, padded_widths, colaligns, fmt.linebelowheader)
+            _append_line(lines, padded_widths, colaligns, fmt.linebelowheader, padding=pad)
 
     if rows and fmt.linebetweenrows and "linebetweenrows" not in hidden:
         # initial rows with a line below
@@ -2648,7 +2659,7 @@ def _format_table(
                     fmt.datarow,
                     rowalign=ralign,
                 )
-            _append_line(lines, padded_widths, colaligns, fmt.linebetweenrows)
+            _append_line(lines, padded_widths, colaligns, fmt.linebetweenrows, padding=pad)
         # the last row without a line below
         append_row(
             lines,
@@ -2670,12 +2681,12 @@ def _format_table(
             # test to see if either the 1st column or the 2nd column (account for showindex) has
             # the SEPARATING_LINE flag
             if _is_separating_line(row):
-                _append_line(lines, padded_widths, colaligns, separating_line)
+                _append_line(lines, padded_widths, colaligns, separating_line, padding=pad)
             else:
                 append_row(lines, pad_row(row, pad), padded_widths, colaligns, fmt.datarow)
 
     if fmt.linebelow and "linebelow" not in hidden:
-        _append_line(lines, padded_widths, colaligns, fmt.linebelow)
+        _append_line(lines, padded_widths, colaligns, fmt.linebelow, padding=pad)
 
     if headers or rows:
         output = "\n".join(lines)

test/test_output.py

@@ -369,9 +369,9 @@ def test_simple_headerless_with_sep_line_with_padding_in_tablefmt():
     "Output: simple without headers with sep line with padding in tablefmt"
     expected = "\n".join(
         [
-            "|:-----|---------:|",
+            "| :--- | -------: |",
             "| spam |  41.9999 |",
-            "|:-----|---------:|",
+            "| :--- | -------: |",
             "| eggs | 451      |",
         ]
     )
@@ -489,12 +489,13 @@ def test_github():
     expected = "\n".join(
         [
             "| strings   |   numbers |",
-            "|:----------|----------:|",
+            "| :-------- | --------: |",
             "| spam      |   41.9999 |",
             "| eggs      |  451      |",
         ]
     )
     result = tabulate(_test_table, _test_table_headers, tablefmt="github")
+
     assert_equal(expected, result)
 
 
@@ -506,7 +507,7 @@ def test_github_multiline():
         [
             "|        more | more spam   |",
             "|   spam eggs | & eggs      |",
-            "|------------:|:------------|",
+            "| ----------: | :---------- |",
             "|           2 | foo         |",
             "|             | bar         |",
         ]
@@ -520,7 +521,7 @@ def test_github_with_colalign():
     expected = "\n".join(
         [
             "| Name   |   Age |",
-            "|:-------|------:|",
+            "| :----- | ----: |",
             "| Alice  |    24 |",
             "| Bob    |    19 |",
         ]
@@ -539,7 +540,7 @@ def test_github_no_alignment():
     expected = "\n".join(
         [
             "| strings | numbers |",
-            "|-----------|-----------|",
+            "| --------- | --------- |",
             "| spam | 41.9999 |",
             "| eggs | 451 |",
         ]
@@ -1995,7 +1996,7 @@ def test_pipe():
     expected = "\n".join(
         [
             "| strings   |   numbers |",
-            "|:----------|----------:|",
+            "| :-------- | --------: |",
             "| spam      |   41.9999 |",
             "| eggs      |  451      |",
         ]
@@ -2006,7 +2007,7 @@ def test_pipe():
 
 def test_pipe_headerless():
     "Output: pipe without headers"
-    expected = "\n".join(["|:-----|---------:|", "| spam |  41.9999 |", "| eggs | 451      |"])
+    expected = "\n".join(["| :--- | -------: |", "| spam |  41.9999 |", "| eggs | 451      |"])
     result = tabulate(_test_table, tablefmt="pipe")
     assert_equal(expected, result)
 

test/test_regression.py

@@ -13,7 +13,7 @@ def test_ansi_color_in_table_cells():
     expected = "\n".join(
         [
             "| test   | test   | test   |",
-            "|:-------|:-------|:-------|",
+            "| :----- | :----- | :----- |",
             "| test   | \x1b[31mtest\x1b[0m   | \x1b[32mtest\x1b[0m   |",
         ]
     )
@@ -195,7 +195,7 @@ def test_88_256_ANSI_color_codes():
     expected = "\n".join(
         [
             "| background   | foreground   |",
-            "|:-------------|:-------------|",
+            "| :----------- | :----------- |",
             "| \x1b[48;5;196mred\x1b[49m          | \x1b[38;5;196mred\x1b[39m          |",
         ]
     )
@@ -424,7 +424,7 @@ def test_empty_pipe_table_with_columns():
     "Regression: allow empty pipe tables with columns, like empty dataframes (github issue #15)"
     table = []
     headers = ["Col1", "Col2"]
-    expected = "\n".join(["| Col1   | Col2   |", "|--------|--------|"])
+    expected = "\n".join(["| Col1   | Col2   |", "| ------ | ------ |"])
     result = tabulate(table, headers, tablefmt="pipe")
     assert_equal(expected, result)
 
@@ -542,7 +542,7 @@ def test_numpy_int64_as_integer():
         expected = "\n".join(
             [
                 "|   int |   float |",
-                "|------:|--------:|",
+                "| ----: | ------: |",
                 "|     1 |    3.14 |",
             ]
         )
@@ -596,5 +596,5 @@ def test_asciidoc_without_trailing_whitespace():
 def test_github_escape_pipe_character():
     "Regression: github format must escape pipe character with a backslash (issue #241)"
     result = tabulate([["foo|bar"]], headers=("spam|eggs",), tablefmt="github")
-    expected = "| spam\\|eggs   |\n|:------------|\n| foo\\|bar     |"
+    expected = "| spam\\|eggs   |\n| :---------- |\n| foo\\|bar     |"
     assert_equal(expected, result)