使用正确的标签python绘制图例

Question

我有一个数据框，我想用＆＃39; A＆＃39;＆＃39; B＆＃39;和＆＃39; C＆＃39;但是，我只用A＆＃39; A＆＃39; label：

data = {'A1_mean': [0.457, 1],
         'A2_median': [0.391,1],
         'A3_range': [0.645,1],
         'A4_std': [0.111,1],
         'B1_mean': [0.132,3],
         'B2_median': [0.10,3],
         'B3_range': [0.244,3],
         'B4_std': [0.297,3],
         'C1_mean': [0.286,2],
         'C2_median': [0.231,2],
         'C3_range': [0.554,2],
         'C4_std': [0.147,2]}
df = pd.DataFrame(data).T
color = {1:'red',2:'green',3:'blue'}
ax=df[0].plot(kind='bar',color=df[1].map(color).tolist())
ax.legend(['A','B','C'])

给出：

如何改变这一点，以便我有一个A B和C的传奇，具有适当的颜色（A：红色，B：蓝色，C：绿色）？

Answer 1

根据Legend guide您可以将代理艺术家放置在图例中：

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

data = {'A1_mean': [0.457, 1],
         'A2_median': [0.391,1],
         'A3_range': [0.645,1],
         'A4_std': [0.111,1],
         'B1_mean': [0.132,3],
         'B2_median': [0.10,3],
         'B3_range': [0.244,3],
         'B4_std': [0.297,3],
         'C1_mean': [0.286,2],
         'C2_median': [0.231,2],
         'C3_range': [0.554,2],
         'C4_std': [0.147,2]}
df = pd.DataFrame(data).T
color = {1:'red',2:'green',3:'blue'}
labels = ['A','C','B']
fig, ax = plt.subplots()
df[0].plot(ax=ax, kind='bar', color=df[1].map(color))

handles = []
for i, c in color.items():
    handles.append(mpatches.Patch(color=c, label=labels[i-1]))
plt.legend(handles=handles, loc='best')
# auto-rotate xtick labels
fig.autofmt_xdate()
plt.show()