题解 | #筛选某店铺最有价值用户中消费最多前5名#

import pandas as pd
sales = pd.read_csv('sales.csv')

# 按照结果要求转换类型
sales[['monetary']] = sales[['monetary']].astype('float32')
# 求百分位
des = sales[['recency', 'frequency', 'monetary']].describe().loc['25%':'75%']
# 计算RFM
sales['R_Quartile'] = sales['recency'].apply(lambda x: 4 if x <= des.iloc[0,0] else (3 if x <= des.iloc[1,0] else (2 if x <= des.iloc[2,0] else 1)))
sales['F_Quartile'] = sales['frequency'].apply(lambda x: 1 if x <= des.iloc[0,1] else (2 if x <= des.iloc[1,1] else (3 if x <= des.iloc[2,1] else 4)))
sales['M_Quartile'] = sales['monetary'].apply(lambda x: 1 if x <= des.iloc[0,2] else (2 if x <= des.iloc[1,2] else (3 if x <= des.iloc[2,2] else 4)))
sales['RFMClass']=sales['R_Quartile'].astype(str)+sales['F_Quartile'].astype(str)+sales['M_Quartile'].astype(str) 
print(sales[['user_id','recency','frequency','monetary','RFMClass']].head(5))#输出前五行
print('\n')
data=sales[['user_id','recency','frequency','monetary','RFMClass']].query('RFMClass=="444"')
data=data.sort_values(by='monetary')
print(data.head(5))

散列数据合并成一个字符：

1.先强制类型转换，然后直接相加

2.apply函数映射

3.sort_values(by=排序列）