datetime
데이터 전처리에 유용하게 쓰이는 datetime 라이브러리를 알아봅시다
date='2022-10-18'
print(date)
print(type(date))
2022-10-18
<class 'str'>
from datetime import datetime, timedelta
date=datetime.strptime(date,'%Y-%m-%d')
print(date)
print(type(date))
2022-10-18 00:00:00
<class 'datetime.datetime'>
date=date.strftime('%Y-%m-%d')
print(date)
print(type(date))
2022-10-18
<class 'str'>
date=20221018
print(date)
print(type(date))
20221018
<class 'int'>
date=str(date)
print(date)
print(type(date))
20221018
<class 'str'>
from datetime import datetime, timedelta
date=datetime.strptime(date,'%Y%m%d')
print(date)
print(type(date))
2022-10-18 00:00:00
<class 'datetime.datetime'>
date=date.strftime('%Y%m%d')
print(date)
print(type(date))
20221018
<class 'str'>
date=int(date)
print(date)
print(type(date))
20221018
<class 'int'>
import pandas as pd
from pandas import Series,DataFrame
df = pd.DataFrame({'date' : [20221018,20221019,20221014,20221004]})
df['date']
0 20221018
1 20221019
2 20221014
3 20221004
Name: date, dtype: int64
df['date'] = df['date'].astype(str)
df['date']
0 20221018
1 20221019
2 20221014
3 20221004
Name: date, dtype: object
df['date'] = pd.to_datetime(df['date'])
df['date'] = df['date'].dt.tz_localize('UTC')
print(df['date'])
0 2022-10-18 00:00:00+00:00
1 2022-10-19 00:00:00+00:00
2 2022-10-14 00:00:00+00:00
3 2022-10-04 00:00:00+00:00
Name: date, dtype: datetime64[ns, UTC]
from datetime import date
d = date(2022, 10, 18)
print(d.year) # 년
print(d.month) # 월
print(d.day) # 일
print(d.isoweekday()) # 주
print(d.weekday()) # 요일 (월요일은 0이고 일요일은 6)
2022
10
18
2
1
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