Python Program to rotate a complex no by 180

I want to rotate a complex no by 180° and this code is in my textbook but it gives me a error everytime

import matplotlib.pyplot as plt
x = 2 + 4j
plt.scatter (x.real, x.imag, color='red')
plt.scatter (-1 x.real, -1 x.imag, color = 'blue')
plt.show ()

Desired Output I want output something like that