make matplotlib animation to pause at every frame

Question

How to make an animation plot in matplotlib such that it will pause at every frame until receiving an action from keyboard or mouse?

Essentially, I would like to control the animation such that it could play frame by frame?

The following codes is from the official document. It will only pause/resume with a keyboard action. But I need to control it by every frame.

import matplotlib.pyplot as plt
import numpy as np

import matplotlib.animation as animation


class PauseAnimation:
    def __init__(self):
        fig, ax = plt.subplots()
        ax.set_title('Click to pause/resume the animation')
        x = np.linspace(-0.1, 0.1, 1000)

        # Start with a normal distribution
        self.n0 = (1.0 / ((4 * np.pi * 2e-4 * 0.1) ** 0.5)
                   * np.exp(-x ** 2 / (4 * 2e-4 * 0.1)))
        self.p, = ax.plot(x, self.n0)

        self.animation = animation.FuncAnimation(
            fig, self.update, frames=200, interval=50, blit=True)
        self.paused = False

        fig.canvas.mpl_connect('button_press_event', self.toggle_pause)

    def toggle_pause(self, *args, **kwargs):
        if self.paused:
            self.animation.resume()
        else:
            self.animation.pause()
        self.paused = not self.paused

    def update(self, i):
        self.n0 += i / 100 % 5
        self.p.set_ydata(self.n0 % 20)
        return (self.p,)


pa = PauseAnimation()
plt.show()