String builder optimization (ARCH2071)

Key python.performance.string-builder-optimization · Severity info · Category performance

Chaining many fragments with + in one expression is unreadable and allocates needless intermediate strings. Use join or f-string formatting instead.

Incorrect

def label(user):
    return "Name: " + user.first + " " + user.last + " (" + user.role + ") - " + user.dept + "/" + user.team

Correct

def label(user):
    return f"Name: {user.first} {user.last} ({user.role}) - {user.dept}/{user.team}"

Fix

Replace multi-+ chains with a single f-string or "".join([...]) call.