我目前正在分析一个野外实验中收集的蚯蚓数量数据。我的变量是网站的风格（实验网站与参考地点）、收集数据的年份、栽培的作物和蚯蚓的数量。我使用groupby（）将蚯蚓按类型、年份和作物分组，并将其显示在条形图中。
但是当我试图添加相应的标准偏差时，它给了我以下错误：
ValueError：'yerr'（shape：（8，））必须是标量或1D或（2，n）类数组，其形状匹配'y'（形状：（4，））
我不能解决这个问题，我对Python（和stackoverflow）还很陌生。任何提示将不胜感激！
下面是我的代码：

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

data = {'Style': ["Experiment","Reference", "Experiment", "Reference", "Experiment","Reference",
                  "Experiment", "Reference"],
        'Year': ["2021", "2021","2022","2022", "2021","2021", "2022", "2022"],
        'Crop': ["Rapeseed", "Rapeseed", "Rapeseed", "Rapeseed",
                 "Maize", "Maize", "Maize", "Maize"],
        'Earthworms': [55, 2, 2,6,0,1,7,22]
       }

df = pd.DataFrame(data)

#Set graph properties
fig, ax = plt.subplots(figsize=(15,7))
colors = {"Maize": "#de8f05", "Rapeseed":"#d7bb19"}         
labels = list(colors.keys())

#Create yerr variable
yerr = [10.6926766215636, 1.4142135623731, 0.577350269189626,1.414213562, 0,
        0.707106781186548, 2.857738033, 4.43471156521669]

#Groupby Year, Patchstyle, Crop (ind. variables), EW_num (dep. variable)
df = df.groupby(["Year", "Style", "Crop"])["Earthworms"].sum().unstack().plot.bar(ax=ax, color=colors,     yerr=yerr)

#Assign labels, axis ticks + limit, hide spines  

plt.ylabel("N", size=13, labelpad=10)
plt.yticks(fontsize=12)
plt.xticks(fontsize=12)
ax.set(xlabel=None)

plt.ylim(0,60)    
ax.spines.right.set_visible(False)
ax.spines.top.set_visible(False)
ax.margins(0.2,0)

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