forget the past.

forget the past.

1 files changed, 958 insertions, 0 deletions

diff --git a/table.py b/table.py
new file mode 100644
index 0000000..5d9b5b2
--- /dev/null
+++ b/table.py
@@ -0,0 +1,958 @@
+"""Table management module
+"""
+
+__revision__ = '$Id: table.py,v 1.18 2006-04-09 22:30:53 nico Exp $'
+
+from warnings import warn
+
+from logilab.common.compat import enumerate, sum, set
+
+class Table(object):
+    """Table defines a data table with column and row names.
+    inv:
+        len(self.data) <= len(self.row_names)
+        forall(self.data, lambda x: len(x) <= len(self.col_names))
+    """
+
+    def __init__(self, default_value=0, col_names=None, row_names=None):
+        self.col_names = []
+        self.row_names = []
+        self.data = []
+        self.default_value = default_value
+        if col_names:
+            self.create_columns(col_names)
+        if row_names:
+            self.create_rows(row_names)
+        
+    def _next_row_name(self):
+        return 'row%s' % (len(self.row_names)+1)
+
+    def __iter__(self):
+        return iter(self.data)
+    
+    def __eq__(self, other):
+        if other is None:
+            return False
+        else:
+            return list(self) == list(other)
+
+    def __ne__(self, other):
+        return not self == other
+
+    def __len__(self):
+        return len(self.row_names)
+    
+    ## Rows / Columns creation #################################################
+    def create_rows(self, row_names):
+        """Appends row_names to the list of existing rows
+        """
+        self.row_names.extend(row_names)
+        for row_name in row_names:
+            self.data.append([self.default_value]*len(self.col_names))
+        
+    def create_columns(self, col_names):
+        """Appends col_names to the list of existing columns
+        """
+        for col_name in col_names:
+            self.create_column(col_name)
+
+    def create_row(self, row_name=None):
+        """Creates a rowname to the row_names list
+        """
+        row_name = row_name or self._next_row_name()
+        self.row_names.append(row_name)
+        self.data.append([self.default_value]*len(self.col_names))
+
+    
+    def create_column(self, col_name):
+        """Creates a colname to the col_names list
+        """
+        self.col_names.append(col_name)
+        for row in self.data:
+            row.append(self.default_value)
+
+    ## Sort by column ##########################################################
+    def sort_by_column_id(self, col_id, method = 'asc'):
+        """Sorts the table (in-place) according to data stored in col_id
+        """
+        try:
+            col_index = self.col_names.index(col_id)
+            self.sort_by_column_index(col_index, method)
+        except ValueError:
+            raise KeyError("Col (%s) not found in table" % (col_id))
+        
+
+    def sort_by_column_index(self, col_index, method = 'asc'):
+        """Sorts the table 'in-place' according to data stored in col_index
+
+        method should be in ('asc', 'desc')
+        """
+        sort_list = [(row[col_index], row, row_name)
+                     for row, row_name in zip(self.data, self.row_names)]
+        # Sorting sort_list will sort according to col_index
+        sort_list.sort()
+        # If we want reverse sort, then reverse list
+        if method.lower() == 'desc':
+            sort_list.reverse()
+        
+        # Rebuild data / row names
+        self.data = []
+        self.row_names = []
+        for val, row, row_name in sort_list:
+            self.data.append(row)
+            self.row_names.append(row_name)
+
+    def groupby(self, colname, *others):
+        """builds indexes of data
+        :returns: nested dictionnaries pointing to actual rows
+        """
+        groups = {}
+        colnames = (colname,) + others
+        col_indexes = [self.col_names.index(col_id) for col_id in colnames]
+        for row in self.data:
+            ptr = groups
+            for col_index in col_indexes[:-1]:
+                ptr = ptr.setdefault(row[col_index], {})
+            ptr = ptr.setdefault(row[col_indexes[-1]],
+                                 Table(default_value=self.default_value,
+                                       col_names=self.col_names))
+            ptr.append_row(tuple(row))
+        return groups
+
+    def select(self, colname, value):
+        grouped = self.groupby(colname)
+        try:
+            return grouped[value]
+        except KeyError:
+            return []
+
+    def remove(self, colname, value):
+        col_index = self.col_names.index(colname)
+        for row in self.data[:]:
+            if row[col_index] == value:
+                self.data.remove(row)
+        
+    
+    ## The 'setter' part #######################################################
+    def set_cell(self, row_index, col_index, data):
+        """sets value of cell 'row_indew', 'col_index' to data
+        """
+        self.data[row_index][col_index] = data
+        
+
+    def set_cell_by_ids(self, row_id, col_id, data):
+        """sets value of cell mapped by row_id and col_id to data
+        Raises a KeyError if row_id or col_id are not found in the table
+        """
+        try:
+            row_index = self.row_names.index(row_id)
+        except ValueError:
+            raise KeyError("Row (%s) not found in table" % (row_id))
+        else:
+            try:
+                col_index = self.col_names.index(col_id)
+                self.data[row_index][col_index] = data
+            except ValueError:
+                raise KeyError("Column (%s) not found in table" % (col_id))
+    
+    
+    def set_row(self, row_index, row_data):
+        """sets the 'row_index' row
+        pre:
+            type(row_data) == types.ListType
+            len(row_data) == len(self.col_names)
+        """
+        self.data[row_index] = row_data
+
+        
+    def set_row_by_id(self, row_id, row_data):
+        """sets the 'row_id' column
+        pre:
+            type(row_data) == types.ListType
+            len(row_data) == len(self.row_names)
+        Raises a KeyError if row_id is not found
+        """
+        try:
+            row_index = self.row_names.index(row_id)
+            self.set_row(row_index, row_data)
+        except ValueError:
+            raise KeyError('Row (%s) not found in table' % (row_id))
+        
+
+    def append_row(self, row_data, row_name=None):
+        """Appends a row to the table
+        pre:
+            type(row_data) == types.ListType
+            len(row_data) == len(self.col_names)
+        """
+        row_name = row_name or self._next_row_name()
+        self.row_names.append(row_name)
+        self.data.append(row_data)
+        
+
+    def insert_row(self, index, row_data, row_name=None):
+        """Appends row_data before 'index' in the table. To make 'insert'
+        behave like 'list.insert', inserting in an out of range index will
+        insert row_data to the end of the list
+        pre:
+            type(row_data) == types.ListType
+            len(row_data) == len(self.col_names)
+        """
+        row_name = row_name or self._next_row_name()
+        self.row_names.insert(index, row_name)
+        self.data.insert(index, row_data)
+    
+
+    def delete_row(self, index):
+        """Deletes the 'index' row in the table, and returns it.
+        Raises an IndexError if index is out of range
+        """
+        self.row_names.pop(index)
+        return self.data.pop(index)
+        
+
+    def delete_row_by_id(self, row_id):
+        """Deletes the 'row_id' row in the table.
+        Raises a KeyError if row_id was not found.
+        """
+        try:
+            row_index = self.row_names.index(row_id)
+            self.delete_row(row_index)
+        except ValueError:
+            raise KeyError('Row (%s) not found in table' % (row_id))
+    
+
+    def set_column(self, col_index, col_data):
+        """sets the 'col_index' column
+        pre:
+            type(col_data) == types.ListType
+            len(col_data) == len(self.row_names)
+        """
+        
+        for row_index, cell_data in enumerate(col_data):
+            self.data[row_index][col_index] = cell_data
+
+
+    def set_column_by_id(self, col_id, col_data):
+        """sets the 'col_id' column
+        pre:
+            type(col_data) == types.ListType
+            len(col_data) == len(self.col_names)
+        Raises a KeyError if col_id is not found
+        """
+        try:
+            col_index = self.col_names.index(col_id)
+            self.set_column(col_index, col_data)
+        except ValueError:
+            raise KeyError('Column (%s) not found in table' % (col_id))
+        
+
+    def append_column(self, col_data, col_name):
+        """Appends the 'col_index' column
+        pre:
+            type(col_data) == types.ListType
+            len(col_data) == len(self.row_names)
+        """
+        self.col_names.append(col_name)
+        for row_index, cell_data in enumerate(col_data):
+            self.data[row_index].append(cell_data)
+        
+
+    def insert_column(self, index, col_data, col_name):
+        """Appends col_data before 'index' in the table. To make 'insert'
+        behave like 'list.insert', inserting in an out of range index will
+        insert col_data to the end of the list
+        pre:
+            type(col_data) == types.ListType
+            len(col_data) == len(self.row_names)
+        """
+        self.col_names.insert(index, col_name)
+        for row_index, cell_data in enumerate(col_data):
+            self.data[row_index].insert(index, cell_data)
+        
+
+    def delete_column(self, index):
+        """Deletes the 'index' column in the table, and returns it.
+        Raises an IndexError if index is out of range
+        """
+        self.col_names.pop(index)
+        return [row.pop(index) for row in self.data]
+
+
+    def delete_column_by_id(self, col_id):
+        """Deletes the 'col_id' col in the table.
+        Raises a KeyError if col_id was not found.
+        """
+        try:
+            col_index = self.col_names.index(col_id)
+            self.delete_column(col_index)
+        except ValueError:
+            raise KeyError('Column (%s) not found in table' % (col_id))
+
+    
+    ## The 'getter' part #######################################################
+
+    def get_shape(self):
+        """Returns a tuple which represents the table's shape
+        """    
+        return len(self.row_names), len(self.col_names)
+    shape = property(get_shape)
+    
+    def __getitem__(self, indices):
+        """provided for convenience"""
+        rows, multirows = None, False
+        cols, multicols = None, False
+        if isinstance(indices, tuple):
+            rows = indices[0]
+            if len(indices) > 1:
+                cols = indices[1]
+        else:
+            rows = indices
+        # define row slice
+        if isinstance(rows,str):
+            try:
+                rows = self.row_names.index(rows)
+            except ValueError:
+                raise KeyError("Row (%s) not found in table" % (rows))
+        if isinstance(rows,int):
+            rows = slice(rows,rows+1)
+            multirows = False
+        else:
+            rows = slice(None)
+            multirows = True
+        # define col slice
+        if isinstance(cols,str):
+            try:
+                cols = self.col_names.index(cols)
+            except ValueError:
+                raise KeyError("Column (%s) not found in table" % (cols))
+        if isinstance(cols,int):
+            cols = slice(cols,cols+1)
+            multicols = False
+        else:
+            cols = slice(None)
+            multicols = True
+        # get sub-table
+        tab = Table()
+        tab.default_value = self.default_value
+        tab.create_rows(self.row_names[rows])
+        tab.create_columns(self.col_names[cols])
+        for idx,row in enumerate(self.data[rows]):
+            tab.set_row(idx, row[cols])
+        if multirows :
+            if multicols:
+                return tab
+            else:
+                return [item[0] for item in tab.data]
+        else:
+            if multicols:
+                return tab.data[0]
+            else:
+                return tab.data[0][0]
+
+    def get_dimensions(self):
+        """Returns a tuple which represents the table's shape
+        """
+        warn('table.get_dimensions() is deprecated, use table.shape instead',
+             DeprecationWarning)
+        return self.shape
+
+    def get_element(self, row_index, col_index):
+        """Returns the element at [row_index][col_index]
+        """
+        warn('Table.get_element() is deprecated, use Table.get_cell instead',
+             DeprecationWarning)
+        return self.data[row_index][col_index]
+
+    def get_cell(self, row_index, col_index):
+        warn('table.get_cell(i,j) is deprecated, use table[i,j] instead',
+             DeprecationWarning)
+        return self.data[row_index][col_index]
+        
+    def get_cell_by_ids(self, row_id, col_id):
+        """Returns the element at [row_id][col_id]
+        """
+        warn('table.get_cell_by_ids(i,j) is deprecated, use table[i,j] instead',
+             DeprecationWarning)
+        try:
+            row_index = self.row_names.index(row_id)
+        except ValueError:
+            raise KeyError("Row (%s) not found in table" % (row_id))
+        else:
+            try:
+                col_index = self.col_names.index(col_id)
+            except ValueError:
+                raise KeyError("Column (%s) not found in table" % (col_id))
+        return self.data[row_index][col_index]
+
+    def get_row(self, row_index):
+        """Returns the 'row_index' row
+        """
+        warn('table.get_row(i) is deprecated, use table[i] instead',
+             DeprecationWarning)
+        return self.data[row_index]
+
+    def get_row_by_id(self, row_id):
+        """Returns the 'row_id' row
+        """
+        warn('table.get_row_by_id(i) is deprecated, use table[i] instead',
+             DeprecationWarning)
+        try:
+            row_index = self.row_names.index(row_id)
+        except ValueError:
+            raise KeyError("Row (%s) not found in table" % (row_id))
+        return self.get_row(row_index)
+
+    def get_column(self, col_index, distinct=False):
+        """Returns the 'col_index' col
+        """
+        warn('table.get_column(i) is deprecated, use table[:,i] instead',
+             DeprecationWarning)
+        col = [row[col_index] for row in self.data]
+        if distinct:
+            return set(col)
+        else:
+            return col
+    
+    def get_column_by_id(self, col_id, distinct=False):
+        """Returns the 'col_id' col
+        """
+        warn('table.get_column_by_id(i) is deprecated, use table[:,i] instead',
+             DeprecationWarning)
+        try:
+            col_index = self.col_names.index(col_id)
+        except ValueError:
+            raise KeyError("Column (%s) not found in table" % (col_id))
+        return self.get_column(col_index, distinct)
+    
+
+    def get_rows(self):
+        """Returns all the rows in the table
+        """
+        warn('table.get_rows() is deprecated, just iterate over table instead',
+             DeprecationWarning)
+        return self.data
+
+
+    def get_columns(self):
+        """Returns all the columns in the table
+        """
+        return [self.get_column(index) for index in range(len(self.col_names))]
+
+    
+    def apply_stylesheet(self, stylesheet):
+        """Applies the stylesheet to this table
+        """
+        for instruction in stylesheet.instructions:
+            eval(instruction)
+        
+
+    def transpose(self):
+        """Keeps the self object intact, and returns the transposed (rotated)
+        table.
+        """
+        transposed = Table()
+        transposed.create_rows(self.col_names)
+        transposed.create_columns(self.row_names)
+        for col_index, column in enumerate(self.get_columns()):
+            transposed.set_row(col_index, column)
+        return transposed
+
+
+    def pprint(self):
+        """returns a string representing the table in a pretty
+        printed 'text' format.
+        """
+        # The maxium row name (to know the start_index of the first col)
+        max_row_name = 0
+        for row_name in self.row_names:
+            if len(row_name) > max_row_name:
+                max_row_name = len(row_name)
+        col_start = max_row_name + 5
+
+        lines = []
+        # Build the 'first' line <=> the col_names one
+        # The first cell <=> an empty one
+        col_names_line = [' '*col_start]
+        for col_name in self.col_names:
+            col_names_line.append(col_name.encode('iso-8859-1') + ' '*5)
+        lines.append('|' + '|'.join(col_names_line) + '|')
+        max_line_length = len(lines[0])
+
+        # Build the table
+        for row_index, row in enumerate(self.data):
+            line = []
+            # First, build the row_name's cell
+            row_name = self.row_names[row_index].encode('iso-8859-1')
+            line.append(row_name + ' '*(col_start-len(row_name)))
+
+            # Then, build all the table's cell for this line.
+            for col_index, cell in enumerate(row):
+                col_name_length = len(self.col_names[col_index]) + 5
+                data = str(cell)
+                line.append(data + ' '*(col_name_length - len(data)))
+            lines.append('|' + '|'.join(line) + '|')
+            if len(lines[-1]) > max_line_length:
+                max_line_length = len(lines[-1])
+
+        # Wrap the table with '-' to make a frame
+        lines.insert(0, '-'*max_line_length)
+        lines.append('-'*max_line_length)
+        return '\n'.join(lines)
+    
+
+    def __repr__(self):
+        return repr(self.data)
+
+    def as_text(self):
+        data = []
+        # We must convert cells into strings before joining them
+        for row in self.data:
+            data.append([str(cell) for cell in row])
+        lines = ['\t'.join(row) for row in data]
+        return '\n'.join(lines)
+    
+
+    
+class TableStyle:
+    """Defines a table's style
+    """
+
+    def __init__(self, table):
+
+        self._table = table
+        self.size = dict([(col_name,'1*') for col_name in table.col_names])
+        # __row_column__ is a special key to define the first column which
+        # actually has no name (<=> left most column <=> row names column)
+        self.size['__row_column__'] = '1*'
+        self.alignment = dict([(col_name,'right')
+                               for col_name in table.col_names])
+        self.alignment['__row_column__'] = 'right'
+
+        # We shouldn't have to create an entry for
+        # the 1st col (the row_column one)
+        self.units = dict([(col_name,'') for col_name in table.col_names])
+        self.units['__row_column__'] = '' 
+       
+    # XXX FIXME : params order should be reversed for all set() methods
+    def set_size(self, value, col_id):
+        """sets the size of the specified col_id to value
+        """
+        self.size[col_id] = value
+
+    def set_size_by_index(self, value, col_index):
+        """Allows to set the size according to the column index rather than
+        using the column's id.
+        BE CAREFUL : the '0' column is the '__row_column__' one !
+        """
+        if col_index == 0:
+            col_id = '__row_column__'
+        else:
+            col_id = self._table.col_names[col_index-1]
+
+        self.size[col_id] = value
+
+
+    def set_alignment(self, value, col_id):
+        """sets the alignment of the specified col_id to value
+        """
+        self.alignment[col_id] = value
+
+
+    def set_alignment_by_index(self, value, col_index):
+        """Allows to set the alignment according to the column index rather than
+        using the column's id.
+        BE CAREFUL : the '0' column is the '__row_column__' one !
+        """
+        if col_index == 0:
+            col_id = '__row_column__'
+        else:
+            col_id = self._table.col_names[col_index-1]
+
+        self.alignment[col_id] = value
+
+
+    def set_unit(self, value, col_id):
+        """sets the unit of the specified col_id to value
+        """
+        self.units[col_id] = value
+
+    
+    def set_unit_by_index(self, value, col_index):
+        """Allows to set the unit according to the column index rather than
+        using the column's id.
+        BE CAREFUL :  the '0' column is the '__row_column__' one !
+        (Note that in the 'unit' case, you shouldn't have to set a unit
+        for the 1st column (the __row__column__ one))
+        """
+        if col_index == 0:
+            col_id = '__row_column__'
+        else:
+            col_id = self._table.col_names[col_index-1]
+
+        self.units[col_id] = value
+    
+
+    def get_size(self, col_id):
+        """Returns the size of the specified col_id
+        """
+        return self.size[col_id]
+    
+
+    def get_size_by_index(self, col_index):
+        """Allows to get the size  according to the column index rather than
+        using the column's id.
+        BE CAREFUL : the '0' column is the '__row_column__' one !
+        """
+        if col_index == 0:
+            col_id = '__row_column__'
+        else:
+            col_id = self._table.col_names[col_index-1]
+
+        return self.size[col_id]
+
+
+    def get_alignment(self, col_id):
+        """Returns the alignment of the specified col_id
+        """
+        return self.alignment[col_id]
+
+
+    def get_alignment_by_index(self, col_index):
+        """Allors to get the alignment according to the column index rather than
+        using the column's id.
+        BE CAREFUL : the '0' column is the '__row_column__' one !
+        """
+        if col_index == 0:
+            col_id = '__row_column__'
+        else:
+            col_id = self._table.col_names[col_index-1]
+
+        return self.alignment[col_id]
+
+
+    def get_unit(self, col_id):
+        """Returns the unit of the specified col_id
+        """
+        return self.units[col_id]
+
+
+    def get_unit_by_index(self, col_index):
+        """Allors to get the unit according to the column index rather than
+        using the column's id.
+        BE CAREFUL : the '0' column is the '__row_column__' one !
+        """
+        if col_index == 0:
+            col_id = '__row_column__'
+        else:
+            col_id = self._table.col_names[col_index-1]
+
+        return self.units[col_id]
+
+
+import re    
+CELL_PROG = re.compile("([0-9]+)_([0-9]+)")
+
+class TableStyleSheet:
+    """A simple Table stylesheet
+    Rules are expressions where cells are defined by the row_index
+    and col_index separated by an underscore ('_').
+    For example, suppose you want to say that the (2,5) cell must be
+    the sum of its two preceding cells in the row, you would create
+    the following rule :
+        2_5 = 2_3 + 2_4
+    You can also use all the math.* operations you want. For example:
+        2_5 = sqrt(2_3**2 + 2_4**2)    
+    """
+    
+    def __init__(self, rules = None):
+        rules = rules or []
+        self.rules = []
+        self.instructions = []
+        for rule in rules:
+            self.add_rule(rule)
+
+
+    def add_rule(self, rule):
+        """Adds a rule to the stylesheet rules
+        """
+        try:
+            source_code = ['from math import *']
+            source_code.append(CELL_PROG.sub(r'self.data[\1][\2]', rule))
+            self.instructions.append(compile('\n'.join(source_code),
+                'table.py', 'exec'))
+            self.rules.append(rule)
+        except SyntaxError:
+            print "Bad Stylesheet Rule : %s [skipped]"%rule
+
+    
+    def add_rowsum_rule(self, dest_cell, row_index, start_col, end_col):
+        """Creates and adds a rule to sum over the row at row_index from
+        start_col to end_col.
+        dest_cell is a tuple of two elements (x,y) of the destination cell
+        No check is done for indexes ranges.
+        pre:
+            start_col >= 0
+            end_col > start_col
+        """
+        cell_list = ['%d_%d'%(row_index, index) for index in range(start_col,
+                                                                   end_col + 1)]
+        rule = '%d_%d=' % dest_cell + '+'.join(cell_list)
+        self.add_rule(rule)
+            
+
+    def add_rowavg_rule(self, dest_cell, row_index, start_col, end_col):
+        """Creates and adds a rule to make the row average (from start_col
+        to end_col)
+        dest_cell is a tuple of two elements (x,y) of the destination cell
+        No check is done for indexes ranges.
+        pre:
+            start_col >= 0
+            end_col > start_col
+        """
+        cell_list = ['%d_%d'%(row_index, index) for index in range(start_col,
+                                                                   end_col + 1)]
+        num = (end_col - start_col + 1)
+        rule = '%d_%d=' % dest_cell + '('+'+'.join(cell_list)+')/%f'%num
+        self.add_rule(rule)
+        
+
+    def add_colsum_rule(self, dest_cell, col_index, start_row, end_row):
+        """Creates and adds a rule to sum over the col at col_index from
+        start_row to end_row.
+        dest_cell is a tuple of two elements (x,y) of the destination cell
+        No check is done for indexes ranges.
+        pre:
+            start_row >= 0
+            end_row > start_row
+        """        
+        cell_list = ['%d_%d'%(index, col_index) for index in range(start_row,
+                                                                   end_row + 1)]
+        rule = '%d_%d=' % dest_cell + '+'.join(cell_list)
+        self.add_rule(rule)
+        
+    
+    def add_colavg_rule(self, dest_cell, col_index, start_row, end_row):
+        """Creates and adds a rule to make the col average (from start_row
+        to end_row)
+        dest_cell is a tuple of two elements (x,y) of the destination cell
+        No check is done for indexes ranges.
+        pre:
+            start_row >= 0
+            end_row > start_row
+        """
+        cell_list = ['%d_%d'%(index, col_index) for index in range(start_row,
+                                                                   end_row + 1)]
+        num = (end_row - start_row + 1)
+        rule = '%d_%d=' % dest_cell + '('+'+'.join(cell_list)+')/%f'%num
+        self.add_rule(rule)
+
+
+
+class TableCellRenderer:
+    """Defines a simple text renderer
+    """
+
+    def __init__(self, **properties):
+        """keywords should be properties with an associated boolean as value.
+        For example :
+            renderer = TableCellRenderer(units = True, alignment = False)
+        An unspecified property will have a 'False' value by default.
+        Possible properties are :
+            alignment, unit
+        """
+        self.properties = properties
+
+
+    def render_cell(self, cell_coord, table, table_style):
+        """Renders the cell at 'cell_coord' in the table, using table_style
+        """
+        row_index, col_index = cell_coord
+        cell_value = table.data[row_index][col_index]
+        final_content = self._make_cell_content(cell_value,
+                                                table_style, col_index  +1)
+        return self._render_cell_content(final_content,
+                                         table_style, col_index + 1)
+        
+
+    def render_row_cell(self, row_name, table, table_style):
+        """Renders the cell for 'row_id' row
+        """
+        cell_value = row_name.encode('iso-8859-1')
+        return self._render_cell_content(cell_value, table_style, 0)
+
+
+    def render_col_cell(self, col_name, table, table_style):
+        """Renders the cell for 'col_id' row
+        """
+        cell_value = col_name.encode('iso-8859-1')
+        col_index = table.col_names.index(col_name)
+        return self._render_cell_content(cell_value, table_style, col_index +1)
+
+    
+
+    def _render_cell_content(self, content, table_style, col_index):
+        """Makes the appropriate rendering for this cell content.
+        Rendering properties will be searched using the
+        *table_style.get_xxx_by_index(col_index)' methods
+
+        **This method should be overriden in the derived renderer classes.**
+        """
+        return content
+
+    
+    def _make_cell_content(self, cell_content, table_style, col_index):
+        """Makes the cell content (adds decoration data, like units for
+        example)
+        """
+        final_content = cell_content
+        if 'skip_zero' in self.properties:
+            replacement_char = self.properties['skip_zero']
+        else:
+            replacement_char = 0
+        if replacement_char and final_content == 0:
+            return replacement_char
+        
+        try:
+            units_on = self.properties['units']
+            if units_on:
+                final_content = self._add_unit(
+                    cell_content, table_style, col_index)
+        except KeyError:
+            pass
+        
+        return final_content
+        
+        
+    def _add_unit(self, cell_content, table_style, col_index):
+        """Adds unit to the cell_content if needed
+        """
+        unit = table_style.get_unit_by_index(col_index)
+        return str(cell_content) + " " + unit
+        
+        
+
+class DocbookRenderer(TableCellRenderer):
+    """Defines how to render a cell for a docboook table
+    """
+
+    def define_col_header(self, col_index, table_style):
+        """Computes the colspec element according to the style
+        """
+        size = table_style.get_size_by_index(col_index)
+        return '<colspec colname="c%d" colwidth="%s"/>\n' % \
+               (col_index, size)
+    
+        
+    def _render_cell_content(self, cell_content, table_style, col_index):
+        """Makes the appropriate rendering for this cell content.
+        Rendering properties will be searched using the
+        *table_style.get_xxx_by_index(col_index)' methods.
+        """
+        try:
+            align_on = self.properties['alignment']
+            alignment = table_style.get_alignment_by_index(col_index)
+            if align_on:
+                return "<entry align='%s'>%s</entry>\n" % \
+                       (alignment, cell_content)
+        except KeyError:
+            # KeyError <=> Default alignment
+            return "<entry>%s</entry>\n" % cell_content
+
+
+class TableWriter:
+    """A class to write tables
+    """
+    
+    def __init__(self, stream, table, style, **properties):
+        self._stream = stream
+        self.style = style or TableStyle(table)
+        self._table = table
+        self.properties = properties
+        self.renderer = None
+        
+
+    def set_style(self, style):
+        """sets the table's associated style
+        """
+        self.style = style
+
+
+    def set_renderer(self, renderer):
+        """sets the way to render cell
+        """
+        self.renderer = renderer
+    
+        
+    def update_properties(self, **properties):
+        """Updates writer's properties (for cell rendering)
+        """
+        self.properties.update(properties)
+
+
+    def write_table(self, title = ""):
+        """Writes the table
+        """
+        raise NotImplementedError("write_table must be implemented !")
+        
+
+
+class DocbookTableWriter(TableWriter):
+    """Defines an implementation of TableWriter to write a table in Docbook
+    """
+
+    def _write_headers(self):
+        """Writes col headers
+        """
+        # Define col_headers (colstpec elements)
+        for col_index in range(len(self._table.col_names)+1):
+            self._stream.write(self.renderer.define_col_header(col_index,
+                                                              self.style))
+        
+        self._stream.write("<thead>\n<row>\n")
+        # XXX FIXME : write an empty entry <=> the first (__row_column) column
+        self._stream.write('<entry></entry>\n')
+        for col_name in self._table.col_names:
+            self._stream.write(self.renderer.render_col_cell(
+                col_name, self._table,
+                self.style))
+            
+        self._stream.write("</row>\n</thead>\n")
+
+
+    def _write_body(self):
+        """Writes the table body
+        """
+        self._stream.write('<tbody>\n')
+        
+        for row_index, row in enumerate(self._table.data):
+            self._stream.write('<row>\n')
+            row_name = self._table.row_names[row_index]
+            # Write the first entry (row_name)
+            self._stream.write(self.renderer.render_row_cell(row_name,
+                                                            self._table,
+                                                            self.style))
+            
+            for col_index, cell in enumerate(row):
+                self._stream.write(self.renderer.render_cell(
+                    (row_index, col_index),
+                    self._table, self.style))
+                
+            self._stream.write('</row>\n')
+            
+        self._stream.write('</tbody>\n')
+
+
+    def write_table(self, title = ""):
+        """Writes the table
+        """
+        self._stream.write('<table>\n<title>%s></title>\n'%(title))
+        self._stream.write(
+            '<tgroup cols="%d" align="left" colsep="1" rowsep="1">\n'%
+            (len(self._table.col_names)+1))
+        self._write_headers()
+        self._write_body()
+        
+        self._stream.write('</tgroup>\n</table>\n')
+
+