Set Basics
Creating and using sets
Interview Relevant: Unique collections
Set Basics
Sets are unordered collections of unique elements.
Code Examples
Basic set operations.
python
1# Create sets
2empty = set() # NOT {} (that's a dict!)
3nums = {1, 2, 3, 4, 5}
4from_list = set([1, 2, 2, 3]) # {1, 2, 3}
5
6# Sets remove duplicates
7{1, 1, 2, 2, 3} # {1, 2, 3}
8
9# Membership test O(1)
103 in nums # True
11
12# Length
13len(nums) # 5
14
15# Iterate (order not guaranteed)
16for n in nums:
17 print(n)
18
19# Sets are mutable
20nums.add(6)
21nums.remove(1)