'Add a new entry to the sorted array.
Parameters
key : tuple
Column values at the given row
row : int
Row number'

def add(self, key, row):

    pos = self.find_pos(key, row)
    if (self.unique and (0 <= pos < len(self.row_index)) and all(((self.data[pos][i] == key[i]) for i in range(len(key))))):
        raise ValueError(u'Cannot    add    duplicate    value    "{0}"    in    a    unique    index'.format(key))
    self.data.insert_row(pos, key)
    self.row_index = self.row_index.insert(pos, row)
