It's easy to get the nth occurrence of a dateutil.rrule.rrule instance:
rule = dateutil.rrule.rrule(...)
occurrence = rule[15]
...But I have an occurrence such that occurrence in rule is True; I would like to know which occurrence it is (i.e. the index of the occurrence, which is 15 in the above example) without causing performance problems, as I may need to do this with a lot of occurrences.
Is this possible, and if so, how would it be done?
I am not aware of a method that would allow you to run a test on values with the current set of functions.
However, depending of how frequently you perform your calculations, you might consider doing the followings:
cache feature:cache – If given, it must be a boolean value specifying to enable or disable caching of results. If you will use the same rrule instance multiple times, enabling caching will improve the performance considerably.
Given r being a large set of results:
>>> r # Your result set
<dateutil.rrule.rrule object at 0x7f616d4182e8>
>>> r[1] # Example of what's inside
datetime.datetime(2015, 1, 1, 0, 0)
>>> import numpy as np # Let's load numpy
>>> a = np.array(list(r)) # We build a numpy array, should be fast
>>> np.argwhere(a == datetime.datetime(2015, 1, 1, 0, 0)) # Catch'em all!
array([[1]])
I am unsure if np.argwhere() will be faster than iterating over the result set with a simple loop, but this is a more readable approach.
