【python】time

time加减法

import datetime
from datetime import date
last_time = (date.today() - datetime.timedelta(days=7)).strftime("%Y%m%d")
today_time = date.today().strftime("%Y%m%d")
print(last_time, today_time)

import pandas as pd
from datetime import datetime

df = pd.read_csv("a.txt", sep="\t", header=None)
df.columns = ['query', 'time_str']
# strftime 是 datetime 转成 string
# strptime 是 string 转成 datetime
df['time_str'] = df['time_str'].apply(lambda x : datetime.strptime(x, '%Y-%m-%d %H:%M:%S'))
df['day_diff'] = df.apply(lambda x : (datetime.strptime(datetime.now().strftime('%Y-%m-%d %H:%M:%S'),'%Y-%m-%d %H:%M:%S') - x[1]).days, axis = 1)