Put the legend of pandas bar plot with secondary y axis in front of bars

问题

I have a pandas DataFrame with a secondary y axis and I need a bar plot with the legend in front of the bars. Currently, one set of bars is in front of the legend. If possible, I would also like to place the legend in the lower-left corner. Any ideas appreciated!

I have attempted to set the legend=false and add a custom legend, but it has the same issue. I've tried reordering the columns but there's no way to clear a space for this on the chart.

import pandas as pd
import matplotlib.pyplot as plt

df_y = pd.DataFrame([['jade',12,800],['lime',12,801],['leaf',12,802], 
       ['puke',12,800]], columns=['Territory','Cuisines','Restaurants'])
df_y.set_index('Territory', inplace=True)

plt.figure()
ax=df_y.plot(kind='bar', secondary_y=['Restaurants'])
ax.set_ylabel('Cuisines')
ax.right_ax.set_ylabel('Restaurants')
plt.show()

One set of bars appears behind the legend, and one set appears in front of the legend. The link below goes to an image showing the problem. Thank you!

回答1:

You can create the legend yourself.

Use the color cycler to get the colors correct when zipped with the columns. Make sure to set legend=False in the barplot. loc=3 is the lower left.

import matplotlib.patches as mpatches
import matplotlib.pyplot as plt

fig, ax = plt.subplots()
df_y.plot(kind='bar', secondary_y=['Restaurants'], legend=False, ax=ax)
ax.set_ylabel('Cuisines')
ax.right_ax.set_ylabel('Restaurants')

L = [mpatches.Patch(color=c, label=col) 
     for col,c in zip(df_y.columns, plt.rcParams['axes.prop_cycle'].by_key()['color'])]

plt.legend(handles=L, loc=3)
plt.show()

来源：https://stackoverflow.com/questions/56876823/put-the-legend-of-pandas-bar-plot-with-secondary-y-axis-in-front-of-bars