我想按一列(标签)分组并总结相应的数量(数量)。相关参考号列应以逗号分隔
import pandas as pd
tag = ['PO_001045M100960','PO_001045M100960','PO_001045MSP2526','PO_001045M870191', 'PO_001045M870191', 'PO_001045M870191']
reference= ['PA_000003', 'PA_000005', 'PA_000001', 'PA_000002', 'PA_000004', 'PA_000009']
qty=[4,2,2,1,1,1]
df = pd.DataFrame({'tag' : tag, 'reference':reference, 'qty':qty})
tag reference qty
PO_001045M100960 PA_000003 4
PO_001045M100960 PA_000005 2
PO_001045MSP2526 PA_000001 2
PO_001045M870191 PA_000002 1
PO_001045M870191 PA_000004 1
PO_001045M870191 PA_000009 1
如果我使用df.groupby('tag')['qty']。sum()。reset_index(),则会得到以下结果。
tag qty
ASL_PO_000001045M100960 6
ASL_PO_000001045M870191 3
ASL_PO_000001045MSP2526 2
我需要附加一列,其参考编号为。分别添加到各个标签下,例如
tag qty refrence
ASL_PO_000001045M100960 6 PA_000003, PA_000005
ASL_PO_000001045M870191 3 PA_000002, PA_000004, PA_000009
ASL_PO_000001045MSP2526 2 PA_000001
我该如何实现?
谢谢。
答案 0 :(得分:3)
使用pandas.DataFrame.groupby.agg
:
df.groupby('tag').agg({'qty': 'sum', 'reference': ', '.join})
输出:
reference qty
tag
PO_001045M100960 PA_000003, PA_000005 6
PO_001045M870191 PA_000002, PA_000004, PA_000009 3
PO_001045MSP2526 PA_000001 2
注意:如果reference
列为数字,则', '.join
将不起作用。在这种情况下,请使用lambda x: ', '.join(str(i) for i in x)