Creating Dictionaries and Lists in Python

Dict and List comprehensions are concise, readable ways to create dictionaries and lists in Python. They follow a clear and easily understandable syntax for iterating over sequences and conditionally including elements in your new list or dictionary.

List Comprehension

A list comprehension provides a way to construct lists in a single line of code. It includes an expression followed by a for clause, and then zero or more if or for clauses. An example of a list comprehension is [x**2 for x in range(10)] which would create a list of squares for numbers from 0 to 9.

Dict Comprehension

Similarly, a dict comprehension is used to create dictionaries with a similar syntax. An example would be {x: x**2 for x in range(10)} creating a dictionary where each key-value pair maps an integer to its square.