What methods can prevent or resolve collisions when using hash tables?

Hash collisions in hash tables occur when different keys have the same hash code. The main methods for preventing and resolving collisions:

1. Chaining method — each cell in the table stores a linked list of elements with the same hash. When a collision occurs, the new element is added to the list.

2. Open addressing — upon collision, the next free cell is sought according to a certain sequence (linear probing, quadratic probing, double hashing).

3. Double hashing — when a collision occurs, a second hash function is used to determine the step size for searching for a free cell.

In Python, dictionaries are implemented using open addressing with optimizations, which ensures fast operation and minimal collisions.