What is the difference between lists, tuples, and sets?

In the Python programming language, there are several built-in data structures for storing collections of elements, each of which has a unique purpose and specific properties. Understanding the differences between lists, tuples, sets, and dictionaries helps developers write more efficient, optimized, and secure code by choosing the right tool for specific project tasks.

The first type is lists (list), which are ordered mutable collections of elements denoted by square brackets, for example [1, 2, 3]. You can add, delete, and modify elements inside a list after its creation, as well as store duplicate data and mixed types of elements within it.

The second type is tuples (tuple), which are structurally similar to lists but are immutable collections written in parentheses, for example (1, 2, 3). Since tuples cannot be modified after creation, they consume less RAM, work faster, and can be used as dictionary keys due to their hashability.

The third type is sets (set), which are unordered collections of unique elements enclosed in curly braces, for example {1, 2, 3}. The main feature of sets is the automatic removal of any duplicates upon creation and high speed when checking for the existence of an element in the collection.

The fourth fundamental data type is dictionaries (dict), which store information in key-value pair formats. Dictionaries allow you to quickly find data by a unique key, while keys must be immutable and hashable objects, whereas values can be any Python objects.