Ask input in the middle of animation - python-3.x

Question

What I want do do is to ask for a number in the middle of the animation, for in the future be able to animate n circles and be able to change it in the middle of the animation. But when I try asking for an input I get this:
QCoreApplication::exec: The event loop is already running
and the next frame doesn't start until i have given it an input
How do I try getting an input and if not, continue the animation with the past value?
import numpy as np
import matplotlib.pyplot as plt
from matplotlib.animation import FuncAnimation
import random
fig, ax = plt.subplots()
ax.set_xlim(0,100)
ax.set_ylim(0,100)
alphas = [0.5,0.5]
circle = plt.Circle((5, 10), 10, color='b', fill=True, alpha = alphas[0])
circle2 = plt.Circle((5, 10), 5, color='r', fill=True, alpha = alphas[1])
circles = [circle, circle2]
def init():
for i in circles:
i.center = (50,50)
ax.add_patch(i)
return circles
def animation_frame(k):
try:
num = int(input())
except:
pass
finally:
for j in circles:
x,y = j.center
r = random.uniform(-5,5)
r2 = random.uniform(-5,5)
#stop circles from going out
if (((x + j.radius + r) <= 100 ) & ((x - j.radius + r) >= 0 )):
x += r
else:
x -= r
if (((y + j.radius + r2) <= 100 ) & ((y - j.radius + r2) >= 0 )):
y += r2
else:
y -= r2
j.center = (x, y)
return circles
animation = FuncAnimation(fig,animation_frame, init_func=init,frames=360,interval=20,blit=True)
plt.show()