How to evaluate the time complexity of insert, get, search, and delete operations in a dictionary?

In a dictionary, operations typically have the following time complexities:

• Insertion (insert): O(1) on average
• Data retrieval (lookup): O(1) on average
• Search (search): O(1) on average, as search is a key-based retrieval
• Deletion (delete): O(1) on average

This is achieved thanks to the hash table underlying the dictionary. In the worst case (with collisions), operations can degrade to O(n), but such cases are rare with good implementation and hash distribution.