Remove an exact prefix or suffix

These methods remove one complete match at the chosen end. They return an independent string inside a Result, leaving the original usable:

def title(name: &str) -> Result[str, AllocError]:
    name.removeprefix("draft-")?.removesuffix(".txt")

def main() -> Result[(), AllocError | IoError]:
    name = "draft-notes.txt"
    print(title(&name)?)?
    print("abab".removeprefix("ab")?)?
    print("notes.txt".removesuffix(".csv")?)?
    Ok(())

notes
ab
notes.txt

Empty patterns do nothing. Each method can fail to allocate even when the contents stay unchanged. Use strip for surrounding whitespace instead.