利用python itemgetter和groupby进行字典分组迭代

参考《python cookbook》

如下例子，我们想对字典中的数据按照日期进行分组迭代。

#!/usr/bin/python3
# -*- coding: utf-8 -*-
# @Time    : 2024/8/5 下午10:14
# @Author  : s
from operator import itemgetter
from itertools import groupby

rows=[{'address':'5412 N CLARK','date':'07/01/2012'},
      {'address':'5148 N CLAR','date':'07/04/20121'},
      {'address':'5800 E 58TH','date':'07/02/2012'},
      {'address':'2122 N CLARK','date':'07/03/2012'},
      {'address':'5645 N RAVENSWOOD','date':'07/02/2012'},
      {'address': '1060 W ADDISON','date':'07/02/2012'},
      {'address': '4801 N BROADWAY','date':'07/01/2012'},
      {'address': '1039 WGRANVILLE','date':'07/04/2012'}]

# 根据日期以分组的方式迭代数据
rows.sort(key=itemgetter('date'))
print(rows)
for date, items in groupby(rows, key=itemgetter('date')):
    print(date)
    for i in items:
        print(' ', i)
# 输出结果：
07/01/2012
  {'address': '5412 N CLARK', 'date': '07/01/2012'}
  {'address': '4801 N BROADWAY', 'date': '07/01/2012'}
07/02/2012
  {'address': '5800 E 58TH', 'date': '07/02/2012'}
  {'address': '5645 N RAVENSWOOD', 'date': '07/02/2012'}
  {'address': '1060 W ADDISON', 'date': '07/02/2012'}
07/03/2012
  {'address': '2122 N CLARK', 'date': '07/03/2012'}
07/04/2012
  {'address': '1039 WGRANVILLE', 'date': '07/04/2012'}
07/04/20121
  {'address': '5148 N CLAR', 'date': '07/04/20121'}