pandas绘图图片不显示
注意该文件不能另存为pandas.py
```
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
df = pd.DataFrame(3 * np.random.rand(4), index=['go', 'java', 'c++', 'c'], columns=['L'])
df.plot.pie(subplots=True)
plt.show()
import pandas as pd
import numpy as np
import matplotlib.pyplot as plt
df = pd.DataFrame(3 * np.random.rand(4), index=['go', 'java', 'c++', 'c'], columns=['L'])
df.plot.pie(subplots=True)
plt.savefig('plot.png', dpi=800, bbox_inches='tight')
```
