class Table(object):

    def __init__(self, rows, cols):
        self._rows = rows
        self._cols = cols
        self._table = [[0] * cols for _ in range(rows)]

    def get_value(self, row, col):
        return (self._table[row][col] if 0 <= row < self._rows and 0 <= col < self._cols
                else None)

    def set_value(self, row, col, value):
        self._table[row][col] = value

    def n_rows(self):
        return self._rows

    def n_cols(self):
        return self._cols

    def delete_row(self, row):
        self._table.pop(row)
        self._rows -= 1

    def delete_col(self, col):
        for row in range(self._rows):
            self._table[row].pop(col)
        self._cols -= 1

    def add_row(self, row):
        self._table.insert(row, [0] * self._cols)
        self._rows += 1

    def add_col(self, col):
        for row in range(self._rows):
            self._table[row].insert(col, 0)
        self._cols += 1

def main():
    # Example 1
    tab = Table(3, 5)
    tab.set_value(0, 1, 10)
    tab.set_value(1, 2, 20)
    tab.set_value(2, 3, 30)
    for i in range(tab.n_rows()):
        for j in range(tab.n_cols()):
            print(tab.get_value(i, j), end=' ')
        print()
    print()

    tab.add_row(1)

    for i in range(tab.n_rows()):
        for j in range(tab.n_cols()):
            print(tab.get_value(i, j), end=' ')
        print()
    print()