如何在pandas中聚合多列？

import pandas as pd

# 创建示例DataFrame
data = {
    'Category': ['Electronics', 'Books', 'Electronics', 'Clothing', 'Books'],
    'Sales': [200, 150, 300, 250, 100],
    'Quantity': [10, 5, 15, 10, 4]
}
df = pd.DataFrame(data)

# 使用groupby和agg方法聚合多列
result = df.groupby('Category').agg({'Sales': ['sum', 'mean'], 'Quantity': 'sum'})

print(result)

                Sales          Quantity
                  sum       mean  sum
Category                           
Books             250  125.000000   9
Clothing          250  250.000000  10
Electronics       500  250.000000  25

# 填充缺失值
df_filled = df.fillna(0)

# 或者在agg时忽略缺失值
result = df.groupby('Category').agg({'Sales': ['sum', 'mean'], 'Quantity': 'sum'}, skipna=True)