openai gym's render cannot work with matplotlib

error.py

import matplotlib
# matplotlib.use("TkAgg")
import matplotlib.pyplot as plt
import gym
import numpy as np

def main():
    env = gym.make('CartPole-v0')
    env.reset()
    _ = env.render(mode='rgb_array')
    left = np.array([1, 2, 3, 4, 5])
    height = np.array([100, 300, 200, 500, 400])
    plt.plot(left, height)


if __name__ == '__main__':
    main()

This is the answer !!!!!!!!!!

import matplotlib as mpl
mpl.use('Agg')
import matplotlib.pyplot as plt
import gym
import numpy as np

def main():
    env = gym.make('CartPole-v0')
    env.reset()
    _ = env.render(mode='rgb_array')
    env.close()
    left = np.array([1, 2, 3, 4, 5])
    height = np.array([100, 300, 200, 500, 400])
    plt.plot(left, height)

if __name__ == '__main__':
    main()