set.md

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Lists

Official Documentation

• Sets do not preserve order
• Sets cannot contain multiple instances of the same element
• Checking if an element occurs in the set is very efficient

Creation

# Literal
s = set()          # Empty set
s = { }            # Empty dictionary!!
s = { 1, 2, 3, 4 }

Set Comprehension

s = { x**2 for x in range(1, 5) }
# => { 1, 4, 9, 16 }

Operations

Syntax	Semantics
x in s	Check if x occurs in s
`s1	s2`
s1 - s2	Difference
s1 & s2	Intersection
s.add(x)	Add x to s
s1 < s2	Check if s1 a strict subset of s2
s1 <= s2	Check if s1 a subset of s2
s1 > s2	Check if s1 a strict superset of s2
s1 >= s2	Check if s1 a superset of s2
s.pop()	Removes and returns a random element from s
s.pop(x)	Removes x from s