python: datetime library related finishing

1, datetime general introduction to the library

(1) included in the class

• DATE : Date Object

• Time : Time Object

• timedelta : Interval Object

• datetime : Date Time Object

• tzinfo : time zone information objects

(2) datetime constants contained in block

• MaxYear : Returns the maximum year that can be represented, the return value 9999

• MinYear : Returns the minimum year can be expressed, the return value is 1

2, date class

(1) date objects

　　date objects from the year , month The , Day three parts

date(year, month, day)

　　By year , month The , Day descriptor to access data in the three data

d = datetime.date(2020, 01, 14)
>>>d.year 
2020
>>>d.month
1
>>>d.day
14

　　Can also __getattribute __ () acquires the result of the process:

d = datetime.date(2020, 1, 14)
>>>d.__getattribute__(year)
2020
>>>d.__getattribute__(month)
1
>>>d.__getattribute__(month)
14

(2) date object contains objects and attributes in

　　A method for comparing the size of the date

• __ __eq () : is equal to, for example: X __ .__ EQ (Y)
• __ __ge () : not less than, for example: X .__ GE __ (Y)
• __ __gt () : greater than, for example: X .__ gt __ (Y)
• __ __le () : less than or equal, for example: X .__ Le __ (Y)
• __ __lt () : less than, for example: X .__ lt __ (Y)
• __ __ne () : is not equal to, for example: X .__ NE __ (Y)

　　These methods return values: True / False

　　Gets the number of days between two dates

　　Use __sub __ () and __rsub __ () method, in fact, this method is almost two, is a forward operation, a reverse operation

• __ __sub () : Example: X .__ Sub __ (Y) , corresponding to xy
• __ __rsub () : Example: X .__ RSUB __ (Y) , corresponding to yx

(3) ISO standardized Date

　　Get in line with ISO date standard

• isocalendar () method: returns a tuple of three values of the tuple content (the year, where the first few weeks of years, where the first few days of the week)

>>>d = datetime.date(2020, 5, 14)
>>>d.isocalendar()
(2020, 20, 4)

• isoformat () Method: Returns meet ISO 8601 standard ( YYYY the MM-DD- date strings)

>>>d = datetime.date(2020, 1, 14)
>>>d.isoformat()
2020-01-14
<class 'str'>

• isoweekday () returns in line with ISO first few days of the date specified standard where the current date

>>>d = datetime.date(2020, 1, 14)
>>>d.isoweekday()
2

(4) Other methods and properties

• timetuple (): This method for compatibility time.localtime () Returns a type time.struct_time array, but the element of time thereof was 0

>>>d = datetime.date(2020, 1, 14)
>>>d.timetuple()
>>>time.struct_time(tm_year=2020, tm_mon=1, tm_mday=14, tm_hour=0, tm_min=0, tm_sec=0, tm_wday=1, tm_yday=14, tm_isdst=-1)
>>>d.timetuple().tm_year
2020
>>>d.timetuple().tm_mon
1
>>>d.timetuple().tm_mday
14

• toordinal () : Returns the calendar year to begin several days now, AD 1 of 1 Yue 1 day 1

>>>d = datetime.date(2020, 1, 14)
>>>d.toordinal()
737438

• the replace () : Returns a replacement date fields to develop new date object. . 3 optional parameter, respectively, year , month The , Day . Note that after replacing the heart to produce objects, without affecting the original object data

>>>d = datetime.date(2020, 1, 14)
>>>a = d.replace(2020, 2, 14)
>>>a
2020-02-14

• fromtimestamp (): the given timestamp, returns a date objects

>>>datetime.date.fromtimestamp(time.time())
2020-01-14

• Today () : Returns the current date

>>>datetime.date.today()
>>>print(datetime.date.today())
2020-01-14