📆datetime

from datetime import datetime

datetime 구성요소

#ex)
my_date_time = datetime(my_year, my_month, my_day, my_hour, my_min, my_sec)
my_date_time.hour #시간만 추출

numpy 응용

import numpy as np

시간 배열 생성

#ex)
np.array(['2020-03-15', '2020-03-16', '2020-03-17'], dtype='datetime64[Y]')

• datetime64[’단위’] → 단위: 정밀하게 보고 싶은 단위 (Y, M, D, h, S)
  

np.arange(’시작’, ‘종료’, ‘간격’, ‘간격 단위’)

#ex)
np.arange('2018-06-01', '2018-06-26',7, dtype = 'datetime64[h]')

• 간격 단위 : Y, M, D, h, s

pandas 응용

import pandas as pd

pd.date_range(’시작’, ‘개수’, ‘빈도’)

#ex)
pd.date_range('2020-01-01', peridos=7, freq='D')

#ex)
pd.date_range('Jan 01, 2018', period=7, freq='D')

pd.to_datetime(’날짜’, ‘format’)

#ex)
pd.to_datetime(['1/2/2018', 'Jan 03, 2018'])

#ex)
pd.to_datetime(['2--1--2018', '3--1--2018'], format='%d--%m--%Y')

Ex)

#ex)
data = np.random.randn(3,2)
cols = ['A', 'B']
print(data)

idx = pd.date_range('2020-01-01', periods=3, freq='D')
df = pd.DataFrame(date,index=idx,columns=cols)