使用datetime将字典键从日期转换为月

import datetime

data = {
    datetime.date(2022, 1, 1): 'value1',
    datetime.date(2022, 1, 15): 'value2',
    datetime.date(2022, 2, 1): 'value3',
    datetime.date(2022, 2, 15): 'value4',
}

new_data = {}
for key, value in data.items():
    month = key.strftime('%Y-%m')
    if month in new_data:
        new_data[month].append(value)
    else:
        new_data[month] = [value]

for key, value in new_data.items():
    print(key, value)