Clean and Filter Data with List Comprehensions in Python

Question

Given a list of raw transaction descriptions, strip leading/trailing whitespace, uppercase the strings, and filter out any empty strings or strings starting with '#'.

Accepted Answer

Optimal Solution:
def clean_descriptions(records: list[str]) -> list[str]:
    return [
        cleaned
        for text in records
        if (cleaned := text.strip().upper()) and not cleaned.startswith('#')
    ]

Technical Explanation:
Using a list comprehension combined with the walrus operator (`:=`) strips and uppercases the text once, filtering out falsy empty strings and hashtags.