Insert row into Excel spreadsheet using openpyxl in Python

Question

I'm looking for the best approach for inserting a row into a spreadsheet using openpyxl.

Effectively, I have a spreadsheet (Excel 2007) which has a header row, followed by (at most) a few thousand rows of data. I'm looking to insert the row as the first row of actual data, so after the header. My understanding is that the append function is suitable for adding content to the end of the file.

Reading the documentation for both openpyxl and xlrd (and xlwt), I can't find any clear cut ways of doing this, beyond looping through the content manually and inserting into a new sheet (after inserting the required row).

Given my so far limited experience with Python, I'm trying to understand if this is indeed the best option to take (the most pythonic!), and if so could someone provide an explicit example. Specifically can I read and write rows with openpyxl or do I have to access cells? Additionally can I (over)write the same file(name)?

Answer 1

== Updated to a fully functional version, based on feedback here: groups.google.com/forum/#!topic/openpyxl-users/wHGecdQg3Iw. ==

As the others have pointed out, openpyxl does not provide this functionality, but I have extended the Worksheet class as follows to implement inserting rows. Hope this proves useful to others.

def insert_rows(self, row_idx, cnt, above=False, copy_style=True, fill_formulae=True):
    """Inserts new (empty) rows into worksheet at specified row index.

    :param row_idx: Row index specifying where to insert new rows.
    :param cnt: Number of rows to insert.
    :param above: Set True to insert rows above specified row index.
    :param copy_style: Set True if new rows should copy style of immediately above row.
    :param fill_formulae: Set True if new rows should take on formula from immediately above row, filled with references new to rows.

    Usage:

    * insert_rows(2, 10, above=True, copy_style=False)

    """
    CELL_RE  = re.compile("(?P<col>\$?[A-Z]+)(?P<row>\$?\d+)")

    row_idx = row_idx - 1 if above else row_idx

    def replace(m):
        row = m.group('row')
        prefix = "$" if row.find("$") != -1 else ""
        row = int(row.replace("$",""))
        row += cnt if row > row_idx else 0
        return m.group('col') + prefix + str(row)

    # First, we shift all cells down cnt rows...
    old_cells = set()
    old_fas   = set()
    new_cells = dict()
    new_fas   = dict()
    for c in self._cells.values():

        old_coor = c.coordinate

        # Shift all references to anything below row_idx
        if c.data_type == Cell.TYPE_FORMULA:
            c.value = CELL_RE.sub(
                replace,
                c.value
            )
            # Here, we need to properly update the formula references to reflect new row indices
            if old_coor in self.formula_attributes and 'ref' in self.formula_attributes[old_coor]:
                self.formula_attributes[old_coor]['ref'] = CELL_RE.sub(
                    replace,
                    self.formula_attributes[old_coor]['ref']
                )

        # Do the magic to set up our actual shift    
        if c.row > row_idx:
            old_coor = c.coordinate
            old_cells.add((c.row,c.col_idx))
            c.row += cnt
            new_cells[(c.row,c.col_idx)] = c
            if old_coor in self.formula_attributes:
                old_fas.add(old_coor)
                fa = self.formula_attributes[old_coor].copy()
                new_fas[c.coordinate] = fa

    for coor in old_cells:
        del self._cells[coor]
    self._cells.update(new_cells)

    for fa in old_fas:
        del self.formula_attributes[fa]
    self.formula_attributes.update(new_fas)

    # Next, we need to shift all the Row Dimensions below our new rows down by cnt...
    for row in range(len(self.row_dimensions)-1+cnt,row_idx+cnt,-1):
        new_rd = copy.copy(self.row_dimensions[row-cnt])
        new_rd.index = row
        self.row_dimensions[row] = new_rd
        del self.row_dimensions[row-cnt]

    # Now, create our new rows, with all the pretty cells
    row_idx += 1
    for row in range(row_idx,row_idx+cnt):
        # Create a Row Dimension for our new row
        new_rd = copy.copy(self.row_dimensions[row-1])
        new_rd.index = row
        self.row_dimensions[row] = new_rd
        for col in range(1,self.max_column):
            col = get_column_letter(col)
            cell = self.cell('%s%d'%(col,row))
            cell.value = None
            source = self.cell('%s%d'%(col,row-1))
            if copy_style:
                cell.number_format = source.number_format
                cell.font      = source.font.copy()
                cell.alignment = source.alignment.copy()
                cell.border    = source.border.copy()
                cell.fill      = source.fill.copy()
            if fill_formulae and source.data_type == Cell.TYPE_FORMULA:
                s_coor = source.coordinate
                if s_coor in self.formula_attributes and 'ref' not in self.formula_attributes[s_coor]:
                    fa = self.formula_attributes[s_coor].copy()
                    self.formula_attributes[cell.coordinate] = fa
                # print("Copying formula from cell %s%d to %s%d"%(col,row-1,col,row))
                cell.value = re.sub(
                    "(\$?[A-Z]{1,3}\$?)%d"%(row - 1),
                    lambda m: m.group(1) + str(row),
                    source.value
                )   
                cell.data_type = Cell.TYPE_FORMULA

    # Check for Merged Cell Ranges that need to be expanded to contain new cells
    for cr_idx, cr in enumerate(self.merged_cell_ranges):
        self.merged_cell_ranges[cr_idx] = CELL_RE.sub(
            replace,
            cr
        )

Worksheet.insert_rows = insert_rows