Principles, DateTime-centric, start-up or transit, into the target object, covering the date conversion processing required in most business scenarios
Steps:
1. Mastering several objects and their relationships
2. Understand the basic operation method of each type of object
3. Transforming through transformation relationships
Objects involved
1. DateTime
Copy the Code code as follows:
>>> Import datetime
>>> now = Datetime.datetime.now ()
>>> now
Datetime.datetime (2015, 1, 12, 23, 9, 12, 946118)
>>> type (now)
2. Timestamp
Copy the Code code as follows:
>>> Import Time
>>> Time.time ()
1421075455.568243
3. Time Tuple
Copy CodeThe code is as follows:
>>> Import Time
>>> Time.localtime ()
Time.struct_time (tm_year=2015, Tm_mon=1, tm_mday=12, tm_hour=23, tm_min=10, tm_sec=30, tm_wday=0, tm_yday=12, TM_ISDST =0)
4. String
Copy the Code code as follows:
>>> Import datetime
>>> Datetime.datetime.now (). Strftime ("%y-%m-%d%h:%m:%s")
' 2015-01-12 23:13:08 '
5. Date
Copy the Code code as follows:
>>> Import datetime
>>> Datetime.datetime.now (). Date ()
Datetime.date (2015, 1, 12)
DateTime Basic Operation
1. Get the current datetime
Copy the Code code as follows:
>>> Import datetime
>>> Datetime.datetime.now ()
Datetime.datetime (2015, 1, 12, 23, 26, 24, 475680)
2. Get Date of day
Copy CodeThe code is as follows:
>>> Datetime.date.today ()
Datetime.date (2015, 1, 12)
3. Get tomorrow/The first n days
Tomorrow
Copy the Code code as follows:
>>> datetime.date.today () + Datetime.timedelta (Days=1)
Datetime.date (2015, 1, 13)
three days ago
Copy CodeThe code is as follows:
>>> Datetime.datetime.now ()
Datetime.datetime (2015, 1, 12, 23, 38, 55, 492226)
>>> Datetime.datetime.now ()-Datetime.timedelta (days=3)
Datetime.datetime (2015, 1, 9, 23, 38, 57, 59363)
4. Get the start and end times of the day (00:00:00 23:59:59)
Copy the Code code as follows:
>>> Datetime.datetime.combine (Datetime.date.today (), datetime.time.min)
Datetime.datetime (2015, 1, 12, 0, 0)
>>> Datetime.datetime.combine (Datetime.date.today (), Datetime.time.max)
Datetime.datetime (2015, 1, 12, 23, 59, 59, 999999)
5. Get the time difference of two datetime
Copy CodeThe code is as follows:
>>> (Datetime.datetime (2015,1,13,12,0,0)-Datetime.datetime.now ()). Total_seconds ()
44747.768075
6. Get this week/this month/last day of last month
Week
Copy the Code code as follows:
>>> today = Datetime.date.today ()
>>> today
Datetime.date (2015, 1, 12)
>>> Sunday = Today + Datetime.timedelta (6-today.weekday ())
>>> Sunday
Datetime.date (2015, 1, 18)
Month
Copy the Code code as follows:
>>> Import Calendar
>>> today = Datetime.date.today ()
>>> _, Last_day_num = Calendar.monthrange (today.year, Today.month)
>>> last_day = datetime.date (Today.year, Today.month, Last_day_num)
>>> Last_day
Datetime.date (2015, 1, 31)
Get last last day of the month (possibly across years)
Copy the Code code as follows:
>>> Import datetime
>>> today = Datetime.date.today ()
>>> first = Datetime.date (Day=1, Month=today.month, Year=today.year)
>>> lastmonth = First-datetime.timedelta (Days=1)
Relationship transformation
A transformation between several relationships
Datetime Object/string/timestamp/time Tuple
Relationship Transformation Examples
DateTime <=> String
DateTime-String
Copy the Code code as follows:
>>> Import datetime
>>> Datetime.datetime.now (). Strftime ("%y-%m-%d%h:%m:%s")
' 2015-01-12 23:13:08 '
DateTime, String-
Copy the Code code as follows:
>>> Import datetime
>>> datetime.datetime.strptime ("2014-12-31 18:20:10", "%y-%m-%d%h:%m:%s")
Datetime.datetime (2014, 12, 31, 18, 20, 10)
DateTime <=> Timetuple
DateTime-Timetuple
Copy the Code code as follows:
>>> Import datetime
>>> Datetime.datetime.now (). Timetuple ()
Time.struct_time (tm_year=2015, Tm_mon=1, tm_mday=12, tm_hour=23, tm_min=17, tm_sec=59, tm_wday=0, tm_yday=12, TM_ISDST =-1)
Timetuple, DateTime
Copy the Code code as follows:
Timetuple = timestamp = datetime [look behind Datetime<=>timestamp]
DateTime <=> Date
DateTime-Date
Copy the Code code as follows:
>>> Import datetime
>>> Datetime.datetime.now (). Date ()
Datetime.date (2015, 1, 12)
Date, DateTime
Copy the Code code as follows:
>>> Datetime.date.today ()
Datetime.date (2015, 1, 12)
>>> today = Datetime.date.today ()
>>> Datetime.datetime.combine (Today, Datetime.time ())
Datetime.datetime (2015, 1, 12, 0, 0)
>>> Datetime.datetime.combine (today, Datetime.time.min)
Datetime.datetime (2015, 1, 12, 0, 0)
DateTime <=> Timestamp
DateTime-Timestamp
Copy the Code code as follows:
>>> now = Datetime.datetime.now ()
>>> timestamp = Time.mktime (Now.timetuple ())
>>> Timestamp
1421077403.0
Timestamp, datetime
Copy the Code code as follows:
>>> Datetime.datetime.fromtimestamp (1421077403.0)
Datetime.datetime (2015, 1, 12, 23, 43, 23)
