'Sets an item or row in the matrix.
For Datasheet[i] = v, sets the row at index i to v.
For Datasheet[i,j] = v, sets the value in row i and column j to v.'

def __setitem__(self, index, value):

    if isinstance(index, tuple):
        list.__getitem__(self, index[0])[index[1]] = value
    elif isinstance(index, int):
        self.pop(index)
        self.insert(index, value)
    else:
        raise TypeError('Datasheet    indices    must    be    int    or    tuple')
