How are dictionaries (dicts) implemented and work in Python?

In Python, dictionaries (dict) are implemented as hash tables. Dictionary keys are hashed using the built-in hash() function, which allows for quick retrieval of corresponding values.

Main points of dictionary operation:

• When adding a key-value pair, the hash of the key is computed, determining its position in the array.
• If a collision occurs (two keys with the same hash), open addressing or chaining methods are used to resolve collisions.
• Dictionaries in Python are ordered starting from version 3.7, meaning they preserve the order of element insertion.

Example of using a dictionary:

my_dict = {'apple': 1, 'banana': 2}
print(my_dict['apple'])  # Outputs 1
my_dict['orange'] = 3

This structure provides fast access to elements by key — on average in O(1) time.