Skip to content

dedented triple-quoted strings

triple-quoted strings that open with a newline and have a consistently indented body are auto-dedented at transpile time, so source indentation does not leak into the runtime string value:

def doc():
    return """
        hello
          world
        """

the logical content is "hello\n world" — the common leading indent of each interior line is stripped

trigger conditions

dedenting fires when all of these hold:

  • the string is triple-quoted (""" or ''')
  • the opening quote is immediately followed by a newline ("""\n)
  • the final line before the closing quote is whitespace-only

inline triple-quoted strings ("""one line""") and strings without a newline after the opening quote are left untouched. the rule applies uniformly to plain strings, raw (r"""..."""), f-strings (f"""..."""), t-strings (t"""..."""), and prefixed combinations

closing-quote indent rule

the closing """ must be indented no more than the content's common leading indent. otherwise the rewrite has no consistent dedent depth and the transpiler raises an error:

text = """
  asdf
    """

→ closing """ is indented more than the content of the triple-quoted string

equal indent is fine (content fully dedents). less indent is also fine (content keeps the surplus). this rule only flags the genuinely misaligned case

relationship to PEP 750 / textwrap.dedent

the resulting string is identical to what textwrap.dedent would produce, but there is no runtime call. the rewrite preserves embedded f-string interpolations:

greet = f"""
    hello {name}
    """
# → f"""\
# hello {name}
# """