两组集合的并集

Question

I would like to get the union of two set of sets. Here is the code I have so far in python. I would like it to be as fast as possible as I'm working with a large dataset. Each of the frozensets are no more then 20 elements but there will be somewhere around 50,000 total in a set. All numbers will be between 0 and 100. I expect a fair amount of frozensets that are already in both sets or that when merged will already exist in one of the sets. I'm open to converting to other types if it would allow my program to run faster but I don't want any repeated elements and order is not important.

sets1 = set([frozenset([1,2,3]),frozenset([4,5,6])])
sets2 = set([frozenset([8,9,10]),frozenset([6,7,3])])
newSets = set()
for fset in sets1:
    for fset2 in sets2:
        newS = set(fset)
        newS.update(fset2)
        newSets.add(frozenset(newS))

the correct output is set([1,2,3,8,9,10],[1,2,3,6,7],[3,4,5,6,7],[4,5,6,8,9,10])

Answer 1

You can avoid the temporary set instance and the conversion to a frozenset , by directly "or"ing the frozenset s:

newSets = set()
for fset in sets1:
    for fset2 in sets2:
        newSets.add(fset | fset2)

Further (slight) speedup can be achieved by using set-comprehension:

newSets = { fset|fset2  for fset in sets1  for fset2 in sets2 }