如何更改按箱線圖分組的熊貓中的組標題？

Question

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

df = pd.DataFrame(np.random.randn(10, 3),
                  columns=['Col1', 'Col2', 'Col3'])
df['X'] = pd.Series(['A', 'A', 'A', 'A', 'A',
                     'B', 'B', 'B', 'B', 'B'])
df['Y'] = pd.Series(['A', 'B', 'A', 'B', 'A',
                     'B', 'A', 'B', 'A', 'B'])
boxplot = df.boxplot(column=['Col1', 'Col2'], by=['X', 'Y'])

plt.show()

我想更改兩個標簽Col1和Col2 ，我試圖傳遞參數labels=['Left label','Right label'] （到 matplotlib 核心函數https://matplotlib.org/api/_as_gen/ matplotlib.pyplot.boxplot.html#matplotlib.pyplot.boxplot ）但沒有運氣：

boxplot = df.boxplot(column=['Col1', 'Col2'], by=['X', 'Y'], labels=['Left label','Right label'])

給我錯誤：

ValueError: Dimensions of labels and X must be compatible

Answer 1

試試這個，因為這里的 boxplot 返回一個 NumPy 軸數組，你可以使用這個 NumPy 數組的每個元素和 set_title：

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

df = pd.DataFrame(np.random.randn(10, 3),
                  columns=['Col1', 'Col2', 'Col3'])
df['X'] = pd.Series(['A', 'A', 'A', 'A', 'A',
                     'B', 'B', 'B', 'B', 'B'])
df['Y'] = pd.Series(['A', 'B', 'A', 'B', 'A',
                     'B', 'A', 'B', 'A', 'B'])
ax = df.boxplot(column=['Col1', 'Col2'], by=['X', 'Y'])

ax[0].set_title('AAA')
ax[1].set_title('BBB')

plt.show()

Answer 2

你不妨試試：

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

df = pd.DataFrame(np.random.randn(10, 3),
                  columns=['Col1', 'Col2', 'Col3'])
df['X'] = pd.Series(['A', 'A', 'A', 'A', 'A',
                     'B', 'B', 'B', 'B', 'B'])
df['Y'] = pd.Series(['A', 'B', 'A', 'B', 'A',
                     'B', 'A', 'B', 'A', 'B'])
axes = df.boxplot(column=['Col1', 'Col2'], by=['X', 'Y'])
titles=['Left label','Right label']
for ax, title in zip(axes,titles):
    ax.set_title(title)