python - pandas 按天、周或月分组以获取时间戳

Question

我是 Pandas 初学者。

我有以下数据:

a = [{"content": '1', "time": 1577870427}, 
     {"content": '4', "time": 1577870427},
     {"content": '2', "time": 1577956827},
     {"content": '3', "time": 1580548827}, 
     {"content": '4', "time": 1580635227},
     {"content": '5', "time": 1583054427}, 
     {"content": '6', "time": 1583140827}]

我想要:

2020-01: [
     {"content": '1', "time": '2020-01-01'},
     {"content": '4', "time": '2020-01-01'},
     {"content": '2', "time": '2020-01-02'},
    ]

    2020-02: [
     {"content": '3', "time": '2020-02-01'}, 
     {"content": '4', "time": '2020-02-02'},
    ]

    2020-03: [
     {"content": '5', "time": '2020-03-01'}, 
     {"content": '6', "time": '2020-03-02'}
    ]

Answer 1

您可以通过to_datetime将列时间转换为日期时间带有 unit 参数并用于自定义格式使用 Series.dt.strftime :

df = pd.DataFrame(a)
d = pd.to_datetime(df['time'], unit='s')
df['time'] = d.dt.strftime('%Y-%m-%d')
g = d.dt.strftime('%Y-%m')

d1 = {k: v.to_dict('r') for k, v in df.groupby(g)}