import pandas as pd
from matplotlib import pyplot as plt

# 设置图像大小
plt.rcParams["figure.figsize"] = [7.00, 3.50]
plt.rcParams["figure.autolayout"] = True

# 创建Pandas数据帧
df = pd.DataFrame(
   {
      'activities': ['sleep', 'exercise', 'work', 'study'],
      'hours': [8, 1, 9, 4]
   }
)

# 带有条件标签删除的饼图
df.set_index('activities').plot.pie(y='hours', legend=False, autopct=lambda p: format(p, '.2f') if p > 25 else None)

plt.show()