Matplotlib在使用辅助y轴时未在顶部两个子图中显示xlabel

Question

这个问题与this other one非常相似，但是提供的答案并不完全相同，因此无法解决我的问题。该问题也已提到in this one，但未提供答案。我希望这个例子可以帮助有人指出我的解决方法。

问题是当我使用辅助y轴（同时与pandas和twinx一起使用）时，xlabel和xticklabel消失在顶部子图上。

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之外，坚持使用原始的matplotlib可能是您最好的选择：

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()