parameters: (self, rhs)
return_statement: return result
docstring: Matrix subtraction.
  
          >>> print(MyMatrix([[1, 2],[3, 4]]) - MyMatrix([[5, 6],[7, 8]]))
          [[-4, -4]
           [-4, -4]]
docstring_summary: Matrix subtraction.
docstring_tokens: Matrix subtraction .
function: def __sub__(self, rhs):
          """
          Matrix subtraction.
  
          >>> print(MyMatrix([[1, 2],[3, 4]]) - MyMatrix([[5, 6],[7, 8]]))
          [[-4, -4]
           [-4, -4]]
          """
          m = self.numRows()
          n = self.numCols()
          assert len(rhs) == m
          assert len(rhs[0]) == n
          result = zeros(m,n)
          for i in range(m):
              for j in range(n):
                  result[i][j] = self[i][j] - rhs[i][j]
          return result
function_tokens: def __sub__ ( self , rhs ) : m = self . numRows ( ) n = self . numCols ( ) assert len ( rhs ) == m assert len ( rhs [ 0 ] ) == n result = zeros ( m , n ) for i in range ( m ) : for j in range ( n ) : result [ i ] [ j ] = self [ i ] [ j ] - rhs [ i ] [ j ] return result