Можете подсказать в чем ошибка выдает так:
x1, x2, y1, y2 = int(input("x1, x2, y1, y2 = "))
ValueError: invalid literal for int() with base 10: '1 2 3 4'

def rectangle_parameters(x1, y1, x2, y2, result):
a = abs(x1 - x2)
b = abs(y1 - y2)
print("a = ", a)
print("b = ", b)
result['perimetr'] = 2 * (a + b)
result['ploshad'] = a * b
return

x1, x2, y1, y2 = int(input("x1, x2, y1, y2 = "))
r = {'perimetr' : None, 'ploshad' : None}
rectangle_parameters(x1, y1, x2, y2, r)
print('Perimetr = ', r['perimetr'])
print('Ploshad = ', r['ploshad'])