Use String Remove Affix

Sourcery refactoring id: use-string-remove-affix

Description:

Replaces string slicing with the Python 3.9 features removesuffix and removeprefix.

Before:

if text.startswith("Hello, "):
    text = text[7:]

if text.endswith(" World!"):
    text = text[: -len(" World!")]

After:

text = text.removeprefix("Hello, ")
text = text.removesuffix(" World!")

Explanation:

This refactoring is motivated by PEP 616. As stated in the documentation, using these methods confers several advantages, including being more robust to user error, more performant, and more descriptive.