python plt 設置雙座標軸彩色刻度，雙圖例，標籤旋轉

功能：python matplotlib.pyplot (plt) 雙座標軸，加雙圖例，座標軸刻度加顏色，x橫軸標籤旋轉

代碼：

import matplotlib.pyplot as plt
import numpy as np
np.random.seed(4)

fig = plt.figure()
ax1 = fig.add_subplot(111)
x = ['aaaa','bbbb','cccc','dddd','eeee']
y1 = np.random.rand(5)
y2 = np.random.rand(5)
plot1 = ax1.plot(range(0, len(x)), y1, '-*', color='r', label='train')
ax2 = ax1.twinx()  # this is the important function

plot2 = ax2.plot(range(0, len(x)), y2, '-o', color='g', label='test')
lines = plot1 + plot2

for tl in ax1.get_yticklabels():
    tl.set_color('r')
for tl in ax1.get_xticklabels():
    tl.set_rotation(45)
    tl.set_fontsize(8)
for tl in ax2.get_yticklabels():
    tl.set_color('g')

ax1.legend(lines, [l.get_label() for l in lines]) # only need one legend definition
plt.show()

效果：

感謝：
https://zhuanlan.zhihu.com/p/62020530
https://blog.csdn.net/songrenqing/article/details/78927283