Chaining Interval Operations about portion HOT 4 CLOSED

Thanks for the further explanation.

For anyone who comes across this issue and needs to chain a union using P.empty() as follows allows a chained operation:

from functools import reduce
m = [P.closed(0, 10), P.closed(2, 8), P.closed(1, 4)]
reduce(P.Interval.union, m, P.empty())
>>> [0,10]

from portion.

Hello,

I'm not 100% sure I understood the question, but if I'm right, what you're looking for is reduce from the functools module (see https://docs.python.org/3/library/functools.html#functools.reduce). The function will be P.Interval.intersection, the iterable will be the list of intervals, and the initializer will be the infinite interval (i.e. P.open(-P.inf, P.inf)).

For example:

>>> import portion as P
>>> m = [P.closed(0, 10), P.closed(2, 8), P.closed(1, 4)]
>>> from functools import reduce
>>> reduce(P.Interval.intersection, m, P.open(-P.inf, P.inf))
[2, 4]

Is it what you were looking for?

from portion.

@AlexandreDecan - yes exactly that. I was didn't realise P.Interval.intersection was a class method and hadn't thought of using P.open(-P.inf, P.inf) as the starting point.
Thanks!

from portion.

You're welcome ;-)

Note that P.Interval.intersection is not a class method but, thanks to Python, if a is an instance of class A, then a.f() is (nearly) equivalent to A.f(a), so we can use instance methods as class methods :-)

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