The function return defferentail number and matricies

difference.py

def difference(A,B):
	'''
	The function return defferentail number and matricies.
	parametr A: First variable
	parametr B: Second variable
	...
	return C: result difference
	'''
	if 	type(A)==int and type(B)==int or \
		type(A)==float and type(B)==float:
		return A-B
	else:
		
		m,n,k,p=len(A),len(A[0]),len(B),len(B[0])
		if m!=k or n!=p:
			raise ArithmeticError('Not the same size.')
			
		# Initial zeros matrix
		C=[[0]*n for _ in range(n)]
		# Perform element by element sum
		for i in range(m):
			for j in range(n):
				C[i][j]=A[i][j]-B[i][j]
	return C
	
if __name__=='__main__':
	a=[[4,2],[556,8]]
	b=[[4,1],[550,4]]
	print(difference(a, b))