Python: How to get the sum of timed开发者_如何学编程elta?
Eg. I just got a lot of timedelta object, and now I want the sum. That's it!
To add timedeltas you can use the builtin operator +
:
result = timedelta1 + timedelta2
To add a lot of timedeltas you can use sum:
result = sum(timedeltas, datetime.timedelta())
Or reduce:
import operator
result = reduce(operator.add, timedeltas)
datetime combine method allows you to combine time with a delta
datetime.combine(date.today(), time()) + timedelta(hours=2)
timedelta can be combined using usual '+' operator
>>> timedelta(hours=3)
datetime.timedelta(0, 10800)
>>> timedelta(hours=2)
datetime.timedelta(0, 7200)
>>>
>>> timedelta(hours=3) + timedelta(hours=2)
datetime.timedelta(0, 18000)
>>>
You can read the datetime module docs and a very good simple introduction at
- http://www.doughellmann.com/PyMOTW/datetime/
If you have a list of timedelta objects, you could try:
datetime.timedelta(seconds=sum(td.total_seconds() for td in list_of_deltas))
As this "just works", I assume this question lacks some detail...
Just like this:
>>> import datetime
>>> datetime.timedelta(seconds=10) + datetime.timedelta(hours=5)
datetime.timedelta(0, 18010)
I am pretty sure that by "sum" he means that he wants the value of the sum in a primitive type (eg integer) rather than a datetime object.
Note that you can always use the dir
function to reflect on an object, returning a list of its methods and attributes.
>>> import datetime
>>> time_sum=datetime.timedelta(seconds=10) + datetime.timedelta(hours=5)
>>> time_sum
datetime.timedelta(0, 18010)
>>> dir(time_sum)
['__abs__', '__add__', '__class__', '__delattr__', '__div__', '__doc__', '__eq__', '__floordiv__', '__ge__', '__getattribute__', '__gt__', '__hash__', '__init__', '__le__', '__lt__', '__mul__', '__ne__', '__neg__', '__new__', '__nonzero__', '__pos__', '__radd__', '__rdiv__', '__reduce__', '__reduce_ex__', '__repr__', '__rfloordiv__', '__rmul__', '__rsub__', '__setattr__', '__str__', '__sub__', 'days', 'max', 'microseconds', 'min', 'resolution', 'seconds']
So in this case, it looks like we probably want seconds.
>>> time_sum.seconds
18010
Which looks right to me:
>>> 5*60*60 + 10
18010
(Edit: Assuming that by "sum timedelta" you mean "convert a timedelta to int seconds".)
This is very inefficient, but it is simple:
int((datetime.datetime.fromtimestamp(0) + myTimeDelta).strftime("%s"))
This converts a Unix timestamp (0
) into a datetime object, adds your delta to it, and then converts back to a Unix time. Since Unix time counts seconds, this is the number of seconds your timedelta represented.
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