Pandas计数器作为新列

import pandas as pd

data = {
    'Region': ['North', 'South', 'East', 'West', 'North', 'South'],
    'Product': ['A', 'B', 'A', 'C', 'B', 'A']
}

df = pd.DataFrame(data)

# 统计每个产品在各个地区的销售数量
product_counts = df.groupby('Region')['Product'].value_counts().unstack(fill_value=0)

# 将统计结果添加到原 DataFrame 中
df = df.join(product_counts.add_suffix('_Count'))

print(df)

  Region Product  A_Count  B_Count  C_Count
0  North       A        1        0        0
1  South       B        0        1        0
2   East       A        1        0        0
3   West       C        0        0        1
4  North       B        1        1        0
5  South       A        1        0        0