Create an animated gif using matplotlib (& PIL)

matplotlib_animated_gif.py

# -*- coding: utf-8 -*-
import matplotlib.pyplot as plt
import numpy as np
from matplotlib.animation import FuncAnimation, PillowWriter

# initialize the figure
fig, ax = plt.subplots()
fig.set_tight_layout(True)
ax.set_xlim(0, 2 * np.pi)
ax.set_ylim(-1, 1)

# initialize empty objects
x, y_sin, y_cos = [], [], []
line_1, = plt.plot([], [], 'ro')
line_2, = plt.plot([], [], 'm*')

def update_func(frame: float):
    x.append(frame)
    y_sin.append(np.sin(frame))
    y_cos.append(np.cos(frame))
    line_1.set_data(x, y_sin)
    line_2.set_data(x, y_cos)

# initialize the `FuncAnimation` object
anim = FuncAnimation(
    fig=fig,
    func=update_func,
    frames=np.linspace(0, 2 * np.pi, 64),
    # init_func=init_func
)

# initialize the `Writer` object using 25 frames per second
writer = PillowWriter(fps=25)

# save the animation as a gif
anim.save('demo_sin.gif', writer=writer)