Python Interview Questions

What is the difference between a list and a tuple?

Both are ordered collections, but lists are mutable while tuples are immutable. Use a tuple when the values should not change and a list when the collection needs to be updated.

What is the difference between == and is?

== compares values. is checks whether two references point to the same object. In normal application code, use is None for a None check and == for value comparisons.

What are mutable and immutable objects?

Mutable objects can be changed after creation, such as lists and dictionaries. Immutable objects cannot be changed in place, such as strings, integers, and tuples. This distinction matters when objects are shared between functions.

What is a dictionary comprehension?

A dictionary comprehension creates a dictionary from an iterable in a compact, readable form:

squares = {number: number * number for number in range(5)}