However, many Python programmers dislike it, including Guido himself: About 12 years ago, Python aquired lambda, reduce(), filter() and map(), courtesy of (I believe) a Lisp hacker who missed them and submitted working patches. But, despite of the PR value, I think these features should be cut from Python 3000. So now reduce().

Jul 18, 2022 · Compute the union of the sets using: c = a | b Sets are unordered sequences of unique values. a | b, or a.union(b), is the union of the two sets — i.e., a new set with all values found in either set. This is a class of operations called "set operations", which Python set types are equipped with.

Jul 18, 2022 · Converting to lists and back is a lot of unnecessary overhead and seems to defeat the purpose of sets. Consider the answer by @nyuszika7h as well as the solution in comments (ill copy here): big_set = my_sets[0].union(*my_sets[1:]) –

set.difference, set.union... can take any iterable as the second arg while both need to be sets to use -, there is no difference in the output. Operation Equivalent Result s.difference(t) s - t new set with elements in s but not in t

Jul 3, 2013 · That's because the whole point of a set, both in mathematics and in almost every programming language,* is that it's not ordered: the sets {1, 2} and {2, 1} are the same set. You probably don't really want to sort those elements as strings, but as numbers (so 4.918560000 will come before 10.277200999 rather than after).

Jun 11, 2015 · Union sets of lists/sets in Python. 1. Union of Two Set of Sets. 3. Turning list into set and union ...

Jan 7, 2013 · Yes, Python sets are mutable because we can add, delete elements into set, but sets can't contain mutable items into itself. Like the below code will give an error: s = set([[1,2,3],[4,5,6]]) So sets are mutable but can't contain mutable items, because set internally uses hashtable to store its elements so for that set elements need to be hashable.

It first checks if the sets have the same length, then it checks if the sets have the same hash, and only then it performs set_issubset check. You can find the implementation of set equality check in function set_richcompare() in file setobject.c .

One neat thing about Python is that you can override this behavior in a class of your own. For example, in some languages the ^ symbol means exponentiation. You could do that this way, just as one example: class Foo(float): def __xor__(self, other): return self ** other

In Python, how do I find common words from two lists while preserving word order? (to keep the order) Python -Intersection of multiple lists? (for computing the intersection between >= 3 lists) Intersection of two lists including duplicates? (to keep the duplicate elements)