I am trying to figure out the differences between the datetime and time modules, and what each sh开发者_如何学编程ould be used for.

I know that datetime provides both dates and time. What is the use of the time module?

Examples would be appreciated and differences concerning timezones would especially be of interest.

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The time module is principally for working with Unix time stamps; expressed as a floating point number taken to be seconds since the Unix epoch. the datetime module can support many of the same operations, but provides a more object oriented set of types, and also has some limited support for time zones.

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Stick to time to prevent DST ambiguity.

Use exclusively the system time module instead of the datetime module to prevent ambiguity issues with daylight savings time (DST).

Conversion to any time format, including local time, is pretty easy:

import time
t = time.time()

time.strftime('%Y-%m-%d %H:%M %Z', time.localtime(t))
'2019-05-27 12:03 CEST'

time.strftime('%Y-%m-%d %H:%M %Z', time.gmtime(t))
'2019-05-27 10:03 GMT'

time.time() is a floating point number representing the time in seconds since the system epoch. time.time() is ideal for unambiguous time stamping.

If the system additionally runs the network time protocol (NTP) dæmon, one ends up with a pretty solid time base.

Here is the documentation of the time module.

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The time module can be used when you just need the time of a particular record - like lets say you have a seperate table/file for the transactions for each day, then you would just need the time. However the time datatype is usually used to store the time difference between 2 points of time.

This can also be done using datetime, but if we are only dealing with time for a particular day, then time module can be used.

Datetime is used to store a particular data and time for a record. Like in a rental agency. The due date would be a datetime datatype.

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Just noticed that time is more precise than datetime with an extra digit.

import time as tm
from datetime import datetime as dt
restime = tm.time()
resdtime = dt.timestamp(dt.now())
print("TIME:".rjust(10," "),restime)
print("DATETIME:".rjust(10," "),resdtime)

Output

     TIME: 1637357103.7650678
 DATETIME: 1637357103.765067