MatPlotLib's ion() and draw() not working

Question

I am trying to plot figures in real time using a for loop. I have the following simple code:

import matplotlib.pyplot as plt

plt.ion()
plt.figure()
for i in range(100):
    plt.plot([i], [i], 'o')
    plt.draw()
    plt.pause(0.0001)

This code does not show the figure until it has finished computing, which I don't want. I want it to draw the figure after every loop. If I replace plt.draw() with plt.show, multiple figures are output in real time, but I want them all to appear in the same figure. Any ideas?

EDIT:
I downloaded PyCharm with Anaconda and everything works fine. I guess it's a problem with Spyder since I tried a few different versions of it without success. If anyone has any clue what is causing this problem in Spyder, let me know!

Answer 1

Adapted for your case from : Python realtime plotting

import matplotlib.pyplot as plt
import numpy as np
import time

fig = plt.figure()
ax = fig.add_subplot(111)

# some X and Y data
x = [0]
y = [0]

li, = ax.plot(x, y,'o')

# draw and show it
fig.canvas.draw()
plt.show(block=False)

# loop to update the data
for i in range(100):
    try:
        x.append(i)
        y.append(i)

        # set the new data
        li.set_xdata(x)
        li.set_ydata(y)

        ax.relim() 
        ax.autoscale_view(True,True,True) 

        fig.canvas.draw()

        time.sleep(0.01)
    except KeyboardInterrupt:
        plt.close('all')
        break

Answer 2

This solution example has worked for me on multiple machines. Try adjusting plt.pause(...)

import matplotlib.pyplot as plt
import numpy as np

F = lambda x: np.sin(2*x)

plt.ion()    
x = np.linspace(0, 1, 200)
plt.plot(x, F(x))


for i in range(100):
    if 'ax' in globals(): ax.remove()
    newx = np.random.choice(x, size = 10)
    ax = plt.scatter(newx, F(newx))
    plt.pause(0.05)

plt.ioff()
plt.show()