Can you explain how the set (set) is implemented in Python and how it works internally?

A set in Python is implemented based on a hash table. Inside the set, unique hashable objects are stored, using their hash values for quick access.

Main implementation points:

• Each element of the set is hashed using the __hash__() function.
• Elements are placed in an array (buckets) by an index computed from the hash.
• In case of collisions, open addressing (linear or double probing) is used to find a free slot.
• Operations like adding, removing, and checking for an element work on average in O(1) time.

Example:

s = set()
s.add('apple')  # 'apple' is hashed and placed in the table
print('apple' in s)  # Fast existence check

Thus, the set provides efficient storage of unique elements and quick access to them through hashing.