docutils.parsers.rst.tableparser module

This module defines table parser classes,which parse plaintext-graphic tables and produce a well-formed data structure suitable for building a CALS table.

Classes:

• GridTableParser: Parse fully-formed tables represented with a grid.

• SimpleTableParser: Parse simple tables, delimited by top & bottom borders.

Exception class:

TableMarkupError

Function:

update_dict_of_lists(): Merge two dictionaries containing list values.

exception TableMarkupError(*args, **kwargs)

Bases: DataError

Raise if there is any problem with table markup.

The keyword argument offset denotes the offset of the problem from the table’s start line.

class TableParser

Bases: object

Abstract superclass for the common parts of the syntax-specific parsers.

head_body_separator_pat = None

Matches the row separator between head rows and body rows.

double_width_pad_char = '\x00'

Padding character for East Asian double-width text.

parse(block)

Analyze the text block and return a table data structure.

Given a plaintext-graphic table in block (list of lines of text; no whitespace padding), parse the table, construct and return the data necessary to construct a CALS table or equivalent.

Raise TableMarkupError if there is any problem with the markup.

find_head_body_sep()

Look for a head/body row separator line; store the line index.

class GridTableParser

Bases: TableParser

Parse a grid table using parse().

Here’s an example of a grid table:

+------------------------+------------+----------+----------+
| Header row, column 1   | Header 2   | Header 3 | Header 4 |
+========================+============+==========+==========+
| body row 1, column 1   | column 2   | column 3 | column 4 |
+------------------------+------------+----------+----------+
| body row 2             | Cells may span columns.          |
+------------------------+------------+---------------------+
| body row 3             | Cells may  | - Table cells       |
+------------------------+ span rows. | - contain           |
| body row 4             |            | - body elements.    |
+------------------------+------------+---------------------+

Intersections use ‘+’, row separators use ‘-’ (except for one optional head/body row separator, which uses ‘=’), and column separators use ‘|’.

Passing the above table to the parse() method will result in the following data structure:

([24, 12, 10, 10],
 [[(0, 0, 1, ['Header row, column 1']),
   (0, 0, 1, ['Header 2']),
   (0, 0, 1, ['Header 3']),
   (0, 0, 1, ['Header 4'])]],
 [[(0, 0, 3, ['body row 1, column 1']),
   (0, 0, 3, ['column 2']),
   (0, 0, 3, ['column 3']),
   (0, 0, 3, ['column 4'])],
  [(0, 0, 5, ['body row 2']),
   (0, 2, 5, ['Cells may span columns.']),
   None,
   None],
  [(0, 0, 7, ['body row 3']),
   (1, 0, 7, ['Cells may', 'span rows.', '']),
   (1, 1, 7, ['- Table cells', '- contain', '- body elements.']),
   None],
  [(0, 0, 9, ['body row 4']), None, None, None]])

The first item is a list containing column widths (colspecs). The second item is a list of head rows, and the third is a list of body rows. Each row contains a list of cells. Each cell is either None (for a cell unused because of another cell’s span), or a tuple. A cell tuple contains four items: the number of extra rows used by the cell in a vertical span (morerows); the number of extra columns used by the cell in a horizontal span (morecols); the line offset of the first line of the cell contents; and the cell contents, a list of lines of text.

head_body_separator_pat = re.compile('\\+=[=+]+=\\+ *$')

Matches the row separator between head rows and body rows.

setup(block)

parse_table()

Start with a queue of upper-left corners, containing the upper-left corner of the table itself. Trace out one rectangular cell, remember it, and add its upper-right and lower-left corners to the queue of potential upper-left corners of further cells. Process the queue in top-to-bottom order, keeping track of how much of each text column has been seen.

We’ll end up knowing all the row and column boundaries, cell positions and their dimensions.

mark_done(top, left, bottom, right)

For keeping track of how much of each text column has been seen.

check_parse_complete()

Each text column should have been completely seen.

scan_cell(top, left)

Starting at the top-left corner, start tracing out a cell.

scan_right(top, left)

Look for the top-right corner of the cell, and make note of all column boundaries (‘+’).

scan_down(top, left, right)

Look for the bottom-right corner of the cell, making note of all row boundaries.

scan_left(top, left, bottom, right)

Noting column boundaries, look for the bottom-left corner of the cell. It must line up with the starting point.

scan_up(top, left, bottom, right)

Noting row boundaries, see if we can return to the starting point.

structure_from_cells()

From the data collected by scan_cell(), convert to the final data structure.

class SimpleTableParser

Bases: TableParser

Parse a simple table using parse().

Here’s an example of a simple table:

=====  =====
col 1  col 2
=====  =====
1      Second column of row 1.
2      Second column of row 2.
       Second line of paragraph.
3      - Second column of row 3.

       - Second item in bullet
         list (row 3, column 2).
4 is a span
------------
5
=====  =====

Top and bottom borders use ‘=’, column span underlines use ‘-’, column separation is indicated with spaces.

Passing the above table to the parse() method will result in the following data structure, whose interpretation is the same as for GridTableParser:

([5, 25],
 [[(0, 0, 1, ['col 1']),
   (0, 0, 1, ['col 2'])]],
 [[(0, 0, 3, ['1']),
   (0, 0, 3, ['Second column of row 1.'])],
  [(0, 0, 4, ['2']),
   (0, 0, 4, ['Second column of row 2.',
              'Second line of paragraph.'])],
  [(0, 0, 6, ['3']),
   (0, 0, 6, ['- Second column of row 3.',
              '',
              '- Second item in bullet',
              '  list (row 3, column 2).'])],
  [(0, 1, 10, ['4 is a span'])],
  [(0, 0, 12, ['5']),
   (0, 0, 12, [''])]])

head_body_separator_pat = re.compile('=[ =]*$')

Matches the row separator between head rows and body rows.

span_pat = re.compile('-[ -]*$')

setup(block)

parse_table()

First determine the column boundaries from the top border, then process rows. Each row may consist of multiple lines; accumulate lines until a row is complete. Call self.parse_row to finish the job.

parse_columns(line, offset)

Given a column span underline, return a list of (begin, end) pairs.

init_row(colspec, offset)

parse_row(lines, start, spanline=None)

Given the text lines of a row, parse it and append to self.table.

The row is parsed according to the current column spec (either spanline if provided or self.columns). For each column, extract text from each line, and check for text in column margins. Finally, adjust for insignificant whitespace.

check_columns(lines, first_line, columns)

Check for text in column margins and text overflow in the last column. Raise TableMarkupError if anything but whitespace is in column margins. Adjust the end value for the last column if there is text overflow.

structure_from_cells()

update_dict_of_lists(master, newdata)

Extend the list values of master with those from newdata.

Both parameters must be dictionaries containing list values.