Python 基础 - Day 5 Learning Note - 模块 之 标准库：datetime

Posted 2020-10-03

介绍

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Datetime 模块是time模块的再次封装，提供了更多的接口。主要是日期和时间的解析，格式化及运算。

其他关于时间的模块：

time - basic 

calendar - basic 

pytz - 关于time zones 

dateutil - extension of datetime

常用操作

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 Times类

import datetime

t = datetime.time(1,2,3)   # 01:02:03
print(t)
# 语法： datetime.time(hour,min,sec)

print("hour:", t.hour)  # hour: 1
print(‘minute: ‘, t.minute)  # minute:  2
print(‘second:‘,t.second)
print(‘microsecond:‘,t.microsecond)  
print(‘tzinfo:‘, t.tzinfo)  # time zone info


print(‘earlist:‘, datetime.time.min)  #earlist: 00:00:00
print(‘latest:‘, datetime.time.max) #latest: 23:59:59.999999
print(‘resolution:‘, datetime.time.resolution)  # resolution: 0:00:00.000001  

注意， microsecond毫秒不能用float模式来表示，只能整数。 

Dates类

date类主要用于表示calendar date。属性包括year, month and day。

import datetime

today = datetime.date.today()
print(today)                       # 2017-08-20
print(‘ctime:‘, today.ctime())   # ctime: Sun Aug 20 00:00:00 2017

print(‘ordinal:‘, today.toordinal())  # ordinal: 736561
print("year:", today.year)      # year: 2017
print(‘month:‘,today.month)    # month: 8
print(‘day:‘, today.day)    # day: 20

tuple_today = today.timetuple()
print(tuple_today)  # time.struct_time(tm_year=2017, tm_mon=8, tm_mday=20, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=6, tm_yday=232, tm_isdst=-1)
print(tuple_today.tm_year)  # 提取struct_time里的元素

timedeltas

Date Arithmetic

Comparing values

Combining dates and times

Formatting and parsing 

Time zones