What are nested dictionary comprehensions in Python?

What are nested dictionary comprehensions in Python?

Nested dictionary comprehensions allow you to create dictionaries within dictionaries in a concise way. For example, you can create a dictionary where each key is a number and the value is another dictionary with properties of that number.

Can you give me an example of a nested dictionary comprehension?

Sure! Here's an example: {x: {"square": x2, "cube": x3} for x in range(1, 4)} creates a dictionary with numbers 1 to 3 as keys and their squares and cubes as values.

How does this differ from regular dictionary comprehensions?

The main difference is that in nested dictionary comprehensions, the value itself is another dictionary, allowing for more complex data structures.

Are there any performance considerations I should be aware of?

Yes, while nested comprehensions can be concise, they may be less readable and could impact performance if used excessively. It's important to balance readability and efficiency.