Python对字典数据按照指定的字段进行分组统计

"""
皮蛋编程(https://www.pidancode.com)
创建日期：2022/4/27
功能描述：Python对字典数据按照指定的字段进行分组统计
"""
rows = [
    {'address': '5412 N CLARK', 'date': '07/01/2012'},
    {'address': '5148 N CLARK', 'date': '07/04/2012'},
    {'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 W GRANVILLE', 'date': '07/04/2012'},
]

from itertools import groupby

rows.sort(key=lambda r: r['date'])
for date, items in groupby(rows, key=lambda r: r['date']):
    print(date)
    for i in items:
        print('    ', i)

# Example of building a multidict
from collections import defaultdict
rows_by_date = defaultdict(list)
for row in rows:
    rows_by_date[row['date']].append(row)

for r in rows_by_date['07/01/2012']:
    print(r)

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': '5148 N CLARK', 'date': '07/04/2012'}
     {'address': '1039 W GRANVILLE', 'date': '07/04/2012'}
{'address': '5412 N CLARK', 'date': '07/01/2012'}
{'address': '4801 N BROADWAY', 'date': '07/01/2012'}