python - 如何将图例标签添加为条形图注释？

Question

我想根据出现在条形图的图例中的文本获得注释。请看一下我的最小复制示例:

import matplotlib.pyplot as plt
import pandas as pd
import numpy as np

data = { 'cat1':[np.nan, 0.33, 0.25], 'cat2':[0.4, 0.33, np.nan], 'cat3':[np.nan, np.nan, 0.25]}
df = pd.DataFrame(data)
fig = plt.figure();
ax = df.plot.barh(stacked=True, figsize=(10,8));
ax.grid()
ax.legend()
 
# annotations:
for p in ax.patches:
    left, bottom, width, height = p.get_bbox().bounds
    if width > 0:
         ax.annotate((str(round(width*100))+' %'), xy=(left+width/2, bottom+height/2), 
                    ha='center', va='center')

我得到的看起来像这样:

但我想要这样的输出(在单条中将图例描述作为注释)

我试图从 ax.patches[0].get_label() 中取出注释文本但它给出了输出 '_nolegend_'感谢您的帮助

Answer 1

查看内联代码注释

绘制堆叠条形图时，底部补丁 p ，对应于图例中的拳头值 labels ，首先绘制。

除非 i == 0 , 增加 counter 的值按 1，基于长度 df 的长度，并使用 counter从 labels 索引正确的标签.

在这种情况下，counter将是 0对于前 31 个补丁，然后增加到 1对于第二个 31 个补丁，依此类推。

当每个标签的所有行 (31) 都被绘制时，计数器需要增加。

我将为图例使用不同的调色板，因为当前调色板中所有列的颜色不足

import matplotlib.pyplot as plt
import pandas as pd
import numpy as np
import seaborn as sns

# set up the dataframe
df = pd.read_csv('test.csv')
df.set_index('hyd_yr', inplace=True)

# new color palette
colors = sns.color_palette('husl', n_colors=len(df.columns))

# plot
fig = plt.figure();
ax = df.plot.barh(stacked=True, figsize=(20, 16), color=colors)
ax.grid()
ax.legend()
handles, labels = ax.get_legend_handles_labels()  # extract the legend labels
 
# annotations:
counter = 0  # counter is used to index legend labels
for i, p in enumerate(ax.patches, 0):  #
    if (i % len(df) == 0) & (i != 0):  # reset counter to 0 based on length of df
        counter += 1  # increment the counter
    left, bottom, width, height = p.get_bbox().bounds
    label = labels[counter]  # index the correct label
    if width > 0:
         ax.annotate((f'{label}: {width*100:0.0f}%'), xy=(left+width/2, bottom+height/2), ha='center', va='center')

真实数据在 test.csv

hyd_yr,BM,HFA,HFZ,HM,HNA,HNZ,NWA,NWZ,NZ,SEA,SWA,SWZ,TB,TRM,WA,WS,WZ
1989,,,,,,,,0.0979020979020979,,,,,,,0.3006993006993007,,0.23776223776223776
1990,0.14835164835164835,,,,,,,,,,,,,,0.17582417582417584,,0.21428571428571427
1991,0.23626373626373626,0.08791208791208792,,,,,,,,,,,,,,,0.25824175824175827
1992,,,,0.18032786885245902,,,,,,,,,,,0.16393442622950818,,0.16393442622950818
1993,0.0989010989010989,,,0.12087912087912088,,,,,,,,,,,,,0.22527472527472528
1994,,,0.07142857142857142,,,,,,,0.09340659340659341,,,,,,,0.34615384615384615
1995,,,,0.1043956043956044,,,,0.0989010989010989,,,,,,,,,0.3241758241758242
1996,,0.12571428571428572,,,,,,,0.11428571428571428,,0.13142857142857142,,,,,,
1997,,,,0.08791208791208792,,,,,,,,,,,0.08791208791208792,,0.2032967032967033
1998,,,,,0.08241758241758242,,0.08791208791208792,,,,,,,,,,0.22527472527472528
1999,0.15934065934065933,,,,,,,,,,,,,0.09340659340659341,,,0.23076923076923078
2000,,,,,,,,0.11475409836065574,,,,,,,0.12021857923497267,,0.22404371584699453
2001,,,,,,,,,,,,0.11299435028248588,0.11299435028248588,,,,0.1751412429378531
2002,0.1043956043956044,,,,,,,0.17032967032967034,,,,,,,,,0.2032967032967033
2003,0.11538461538461539,0.11538461538461539,,,,,,,,,,,,,,,0.14285714285714285
2004,0.14207650273224043,,,,,,,,,,,,,0.12568306010928962,,,0.2185792349726776
2005,0.13736263736263737,,,,,,,0.13736263736263737,,,,,,0.2087912087912088,,,
2006,0.13186813186813187,,,,,,,0.15934065934065933,,,,,,0.13736263736263737,,,
2007,0.10989010989010989,,,,,,,,,,,0.16483516483516483,,,,,0.21428571428571427
2008,0.20765027322404372,,,,,,,0.08196721311475409,,,,,,,,,0.28415300546448086
2009,0.11731843575418995,,,,,,,0.12290502793296089,,,,,,0.10614525139664804,,,
2010,,,,,,,,,,,,0.10989010989010989,,,,0.12637362637362637,0.13186813186813187
2011,0.15254237288135594,,,,,,,,,,,0.0903954802259887,,,,,0.11864406779661017
2012,,,,0.10382513661202186,,,,0.18032786885245902,,,,,,,,,0.15300546448087432
2013,,,,,,0.13186813186813187,,,,,,,,0.15934065934065933,,,0.10989010989010989
2014,0.1043956043956044,,,,,,,,,,,0.23076923076923078,,,,,0.08241758241758242
2015,0.12290502793296089,,,,,,,,,,,,,0.1452513966480447,,,0.1340782122905028
2016,,,,,,,,,,,,,,0.09836065573770492,0.1366120218579235,,0.14207650273224043
2017,0.14285714285714285,,,0.14835164835164835,,,,,,,,,,,,,0.13736263736263737
2018,0.1043956043956044,,,,,,,,,,,,,0.12637362637362637,,,0.15934065934065933
2019,0.11363636363636363,,,,,,0.12121212121212122,0.12121212121212122,,,,,,,,,