python - 使用辅助 y 轴时，Matplotlib 在前两个子图中不显示 xlabel

Question

这个问题与this other one非常相似，但提供的答案并不能解决我的问题，因为它并不完全相同。问题也提到了in this one ，但没有提供任何答案。我希望这个例子能帮助别人指出我的解决方法。

问题是当我使用辅助 y 轴时(使用 pandas 和使用 twinx)，xlabels 和 xticklabels 在顶部子图中消失。

import pandas as pd
import matplotlib.pyplot as plt

df = pd.DataFrame([[1,2,4,6],[1,2,6,10],[2,4,12,12],[2,4,12,14],
               [3,8,14,16],[3,8,14,18],[4,10,16,20],[4,10,16,24]], 
              columns =['A','B','C','D'])

fig, axes = plt.subplots(2,2)

for xx, ax in zip(['A','B','C'], axes.flatten()):
    meandf = df.groupby(xx).mean()
    df.plot(xx, 'D', ax = ax, legend=False)

    #adding the secondary_y makes x labels and ticklabels disappear on top subplots
    #without secondary_y it will show the labels and ticklabels
    meandf.plot(meandf.index, 'D', secondary_y='D', ax = ax)

    #forcing does not help
    ax.set_xlabel(xx)

# typically it is a matter of using tight_layout, but does not solve
# setting a bigger space between the rows does not solve it either
plt.tight_layout()

Answer 1

KeyErrors 除了，坚持使用原始 matplotlib 可能是你最好的选择:

import pandas as pd
import matplotlib.pyplot as plt

df = pd.DataFrame(
    [[1, 2, 4, 6], [1, 2, 6, 10], [2, 4, 12, 12], [2, 4, 12, 14],
     [3, 8, 14, 16], [3, 8, 14, 18], [4, 10 ,16, 20], [4, 10 ,16, 24]], 
    columns =['A', 'B', 'C', 'D']
)

fig, axes = plt.subplots(2, 2)

for xx, ax1 in zip(['A','B','C'], axes.flatten()):
    meandf = df.groupby(xx).mean()

    # explicitly create and save the secondary axis  
    ax2 = ax1.twinx()

    # plot on the main ax
    ax1.plot(xx, 'D', 'ko', data=df)

    # plot on the secondary ax
    ax2.plot('D', 'gs', data=meandf)

    # set the label 
    ax1.set_xlabel(xx)

fig.tight_layout()