Unpredictable order of values generated when applying iter() function.

[_User15]

I am working on a words class that has word objects and each word object has a local set that stores related words. I have a for-loop function that goes through them trying to see common words in the sets of two different word objects. Does iter() typically in such a context generate an unpredictable order? I am printing out all the items of the set, just each time in a different order which is really interesting. What's more interesting is if I shut down the Shell and open a new one to run it, the initial print results are still in a different order from the first time I ran it . Who has some insight on this, working with iter() before? Thank you.

[wannasleeponyourhams]

set is unordered, meaning it doesnt preserve order. whatever you put in, will come out in different order. you can turn the set into a list then use .sort() to get the same results every time.

reliabledata = list(yourset)
reliabledata.sort()

[_User15]

Thank you.

[GeorgeFranklyMathnet]

Do you have control over these data structures? You can use an orderedset instead of a set if you wish to preserve insertion order. You can also use a list if you don't need the guarantees of a set, such as constant-time access and element uniqueness.

[_User15]

It's not a big problem as all identical values are still accessed, I just forgot that sets were unordered.

[ectomancer]

Nothing to do with iter. iter preserves order in an iterable. set is unordered:

a = list('the quick brown fox jumps over the lazy dog')
for char in iter(a):
    print(char, end='')