input: Write a function to perform matrix multiplication on two given matrices. Return the resulting matrix after multiplication. If the number of columns in the first matrix is not equal to the number of rows in the second matrix, return an empty list.
  
  def matrix_multiplication(A, B):  
      if len(A[0]) != len(B):  
          return []  
      rows_A = len(A)  
      cols_A = len(A[0])  
      rows_B = len(B)  
      cols_B = len(B[0])  
      result = [[0 for i in range(cols_B)] for j in range(rows_A)]  
      for i in range(rows_A): 
          for j in range(cols_B): 
              for k in range(cols_A): 
                  result[i][j] += A[i][k] * B[k][j] 
      return result
  
  assert matrix_multiplication([[1, 2], [3, 4]], [[1, 0], [0, 1]]) == [[1, 2], [3, 4]]
  assert matrix_multiplication([[1, 2]], [[1], [0]]) == [[1]]
  assert matrix_multiplication([[1, 2, 3], [4, 5, 6]], [[7, 8], [9, 10], [11, 12]]) == [[58, 64], [139, 154]]
  assert matrix_multiplication([[1, 2, 3]], [[1], [1]]) == []
  assert matrix_multiplication([], []) == []
output: def matrix_multiplication(A, B):  
      if len(A[0]) != len(B):  
          return []  
      rows_A = len(A)  
      cols_A = len(A[0])  
      rows_B = len(B)  
      cols_B = len(B[0])  
      result = [[0 for i in range(cols_B)] for j in range(rows_A)]  
      for i in range(rows_A): 
          for j in range(cols_B): 
              for k in range(cols_A): 
                  result[i][j] += A[i][k] * B[k][j] 
      return result