Junior — Middle
Explain how hash tables work in Python's standard library.
sobes.tech AI
Answer from AI
In Python, the standard dictionary (dict) is implemented as a hash table. Key points of operation:
- Keys are hashed using the built-in
hash()function, which returns an integer value. - The hash is used to determine the index in the array where the key-value pair is stored.
- In case of collisions (when different keys produce the same hash), open addressing with probing is used — searching for the next free cell.
- When adding elements, if the table's load factor reaches a certain threshold, resizing and redistribution of elements occur.
This provides amortized constant time complexity for access, insertion, and deletion, close to O(1).
Thus, a dictionary in Python is an efficient data structure for fast key-based lookup, implemented through a hash table with open addressing and dynamic resizing.