What is the reason for the high speed of searching for elements by key in a dictionary data structure?

The dictionary in Python is implemented based on a hash table. The high search speed is achieved because the key is first transformed into a hash code, which points to an index in the array where the value is stored. This allows access to the element in amortized O(1) time, without the need to sequentially iterate over all elements.

Example:

my_dict = {'apple': 1, 'banana': 2, 'orange': 3}
print(my_dict['banana'])  # Fast access by key

The hash function minimizes collisions, which maintains search efficiency.