日期时间数据类型及工具
from datetime import datetime now = datetime.now() print(now.year,now.month,now.day) #以毫秒形式存储时间 delta = now - datetime(1992,2,2) print(delta) print(delta.days) #可以在时间戳上加减乘除 from datetime import timedelta print(delta+timedelta(12))
字符串和datetime转化
#时间转str time_str = now.strftime(‘%y-%m-%d‘) print(time_str) #str转时间 time_str2 = datetime.strptime(time_str,‘%y-%m-%d‘) print(time_str2) #处理成组日期 data_set = [‘2017-1-1‘,‘2018-1-1‘] pd.to_datetime(data_set)
时间序列基础
time_set = [datetime(2017,1,1),datetime(2017,2,1),datetime(2017,3,1),datetime(2017,4,1),datetime(2017,5,1)] data = pd.DataFrame(np.arange(5),index=time_set) data = pd.DataFrame(np.random.randn(1000),index=pd.date_range(‘1992-2-2‘,periods=1000)) #也可以做切片 data[‘1992-3-2‘:]
