python __getitem__ overloading issue
<p>I am trying to implement insert function here. Well, for this class Matrix which is the child class of Grid, seem to have problem. But I don't quite understand what I am doing wrong here. 
The error says "    Grid[m][n] = value TypeError: 'type' object is not subscriptable."</p>

<p>Please help</p>

<p>thanks</p>

<pre><code>from Grid import Grid

class Matrix(Grid):
    def __init__(self, m, n, value=None):
##        super(Matrix, self).__init__(m, n)
        Grid.__init__(self, m, n)

    def insert(self, m, n, value=None):
        Grid[m][n] = value
</code></pre>

<p>here is Grid class</p>

<pre><code>from CArray import Array

class Grid(object):
    """Represents a two-dimensional array."""
    def __init__(self, rows, columns, fillValue = None):
        self._data = Array(rows)
        for row in xrange(rows):
            self._data[row] = Array(columns, fillValue)
    def getHeight(self):
        """Returns the number of rows."""
        return len(self._data)
    def getWidth(self):
        "Returns the number of columns."""
        return len(self._data[0])
    def __getitem__(self, index):
        """Supports two-dimensional indexing 
        with [row][column]."""
        return self._data[index]
    def __str__(self):
        """Returns a string representation of the grid."""
        result = ""
        for row in xrange(self.getHeight()):
            for col in xrange(self.getWidth()):
                result += str(self._data[row][col]) + " "
            result += "\n"
        return result
</code></pre>
