pycharm python 3.7 matplotlib portrait has not presented

A little bit every day, work record in practical operation feasible

code show as below:

import matplotlib.pyplot as plt
import pandas as pd
import numpy as np

lines_df = pd.DataFrame(np.random.randn(1000,2),
                        columns = ['line_a','line_b']).cumsum()
lines_df.plot()

Encountered a situation today, when with pycharm, code can be executed normally, but matplotlib portrait has been no revealed,

But the code in the anaconda executed, there is no question
this is the result of the implementation of spyder:

Later found the problem, plus plt.show () can

plt.show()

If you feel good, please send me a praise yo ~