📅  最后修改于: 2022-03-11 14:46:36.431000             🧑  作者: Mango
# empty set, avoid using {} in creating set or dictionary is created
x = set()
# set {'e', 'h', 'l', 'o'} is created in unordered way
B = set('hello')
# set{'a', 'c', 'd', 'b', 'e', 'f', 'g'} is created
A = set('abcdefg')
# set{'a', 'b', 'h', 'c', 'd', 'e', 'f', 'g'}
A.add('h')
fruit ={'orange', 'banana', 'pear', 'apple'}
# True fast membership testing in sets
'pear' in fruit
'mango' in fruit # False
A == B # A is equivalent to B
A != B # A is not equivalent to B
A <= B # A is subset of B A = B
A > B # A is proper superset of B
A | B # the union of A and B
A & B # the intersection of A and B
A - B # the set of elements in A but not B
A ˆ B # the symmetric difference
a = {x for x in A if x not in 'abc'} # Set Comprehension