[data science] pandas - 날짜와 시간 변경

• 날짜사이에 몇일인지 확인

order_df['day_for_shipping'] = order_df['shipping_time'] - order_df.index

*데이터 타입이 같아야 비교가능.

*데이터 타입을 timedelta로 변경

order_df['days_for_shipping(expected)'] = pd.to_timedelta(order_df['days_for_shipping(expected)'], unit='D')
#unit='H'- 시간단위, S - 초단위 , D - 일단위

#비교 조회
order_df['days_for_shipping(expected)'] < order_df['days_for_shipping(actual)']

order_df['late_shipping'].value_counts()

import pandas as pd

delivery_df = pd.read_csv('data/delivery.csv', parse_dates=['order_time'])



delivery_df['time_taken'] = pd.to_timedelta(delivery_df['time_taken'], unit='T')
delivery_df['delivery_time'] = delivery_df['order_time'] + delivery_df['time_taken']
delivery_df