python1.3-----Time Module/datetime Module/calendar module

Time module:

UTC (World Standard Time): Greenwich Astronomical Time. China time and UTC relationship: China time =utc+8
DST (Daylight saving time): It is a kind of energy saving and it is considered as specified, and it is 1 hours faster in summer.

representation of Time:
1. Time Stamp:
a time interval in seconds for a shape or float to represent the time. The base value for this interval is calculated starting from 0:0 on January 1, 1970.
2. Tuples
A Python data structure that has 9 integer content:
Year : ~
month:~
Day : ~
hours:~
minutes:~
seconds:~
Weekday: Day of the Week (0-6)
Julia Day: One of the Year (1-366)
DST Flag (1: Daylight Saving Time-1: Judging by date self 0: normal format)
3. Format the string:
%Y Four-digit year representation (000-9999)
%m Month (01-12)
One day in%d months (0-31)
%H 24-hour system hours (0-23)
%I 12-hour hours (01-12)
%M minutes (00=59)
%s seconds (00-59)
%f MS (000000-999999)
%a Local Simplified week name
%A Local Full week name
%b a locally simplified month name
%B Local Full month name
%y Two-digit year representation (00-99)
%c Local corresponding date representation and time representation
%j Day of the Year (001-366)
%p the equivalent of a local a.m. or P.M.
%u weeks of the year (00-53) Sunday is the beginning of the week
%w Week (0-6), Sunday for the beginning of the week
%W Week of the Year (00-53) Monday is the beginning of the week
%x Local corresponding date representation
%x Local corresponding time representation
%Z The name of the current time zone
percent% of the number itself

Import time

#三种时间格式的转换:
c=time.time () #以浮点数的形式返回当前时间的时间戳, no parameters are required and the timestamp is assigned to C.
T=time.gmtime (c) #以时间戳为参数, converted to UTC time tuple, not much at Greenwich.
B=time.localtime (c) #以时间戳为参数, converted to local time tuples, with few tuples.
M=time.mktime (b) #将本地时间转为时间戳.
S=time.asctime (b) #将时间元组转为字符串.
P=time.ctime (c) #将时间戳转为字符串.
q=time.strftime ('%y-%m-%d%h:%m:%s ', b) #将b的时间转为格式化字符串形式.
w=time.strptime (q, '%y-%m-%d%h:%m:%s ') #将格式化的时间转化为元组.

Conversion of three time formats:

Other methods of the time module:
Time.sleep (value) #延时value秒, value can be a decimal and an integer.
Time.clock () #返回当前程序的cpu执行时间, Windows starts from the second time, always with the first call to this function's timestamp as the cardinality. Unix always returns the full run time.

Example: Test your computer's computational performance
Import time
Sum=0
Time.clock ()
For I in Range (100000000):
Sum+=i
Print (Time.clock ())

#corei5->16.5 seconds

Datatime module:
The Datatime module is encapsulated based on the time module and provides a more practical function, and the interface of the DateTime module is more intuitive and easier to invoke.

Classes in the module:
DateTime: With both time and date
Timedalta: Main calculation time difference
Tzinfo: Time Zone related
Time: Focus on times only
Date: Focus on dates only

Methods for datetime:
D1=datetime.datetime.now () #获取当前的时间.
d2=datetime.datetime (1999,10,1,10,28,25,123456) #指定一个时间: 1999-10-1 10:28:25.123456
d3=d1.strftime ('%y-%m-%d%x ') #将时间转化为 '%y-%m-%d%x ' format string
D4=datetime.datetime.strptime (D3, '%y-%m-%d%x ') #将格式化字符串转换为datetime对象. The format of the conversion is consistent with the string.
d5=datetime.datetime (1999,10,1,10,28,25,123456)
D6=datetime.datetime.now ()
d7=d6-d5 #时间的减法.
type (D7)-------->datetime.timedalta.
d7.days #间隔的天数
d7.seconds #除天数外间隔的秒数.

Calendar module:
Import Calendar
Calendar.month (Year,month) #返回指定某年某月的日历
Calendar.calendar (year) #返回某年的日历
Calendar.isleap (year) #闰年返回True, otherwise returns false
Calendar.monthrange (Year,month) #返回一个元组 (the first day of the year month of weekday, the total number of days this month)
Calendar.monthcalendar (Year,month) #返回year年第month月每一周为元素的列表

python1.3-----Time Module/datetime Module/calendar module