multiline-closing-quotes-separate-line (PDF109)¶

Part of the PDF rule category.

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Fix is always available.

Rule is incompatible with PDF108.

What it does¶

Checks safely mapped simple multiline docstrings with content and moves same-line closing triple quotes onto their own line.

The generated closing-quote prefix line uses the docstring's canonical continuation margin. For ordinary indented suites this is the existing docstring margin. For simple suites, such as def f(): """Summary."""; return None, it is one configured indentation unit deeper than the containing line.

PDF109 moves the closing quotes without trimming spaces or tabs from the final content line. That whitespace belongs to whitespace-specific rules such as PDF105.

The rule changes docstrings that have at least one content line and span multiple evaluated lines. It does not rewrite blank-only docstrings, docstrings whose closing quotes are already on a separate line, or true one-line docstrings such as """Summary.""".

PDF109 only rewrites safely mapped simple docstring literals. It preserves the original quote delimiter, string prefix, remaining source spelling, and line endings when a rewrite is safe. It skips concatenated docstrings and simple literals where evaluated lines cannot be mapped back to physical source lines safely, such as docstrings that contain escape sequences in a multiline non-raw literal.

Why is this useful?¶

Projects that prefer expanded docstrings can keep the closing delimiter visually separate from the content.

Ruff compatibility¶

This rule is intended to replace Ruff's D209 when pydocformatter is responsible for closing-quote placement.

Examples¶

The canonical PDF109 fix moves same-line closing quotes onto their own line:

def area(radius: float) -> float:
    """Return the area.

    The radius must be non-negative."""

def area(radius: float) -> float:
    """Return the area.

    The radius must be non-negative.
    """

PDF109 preserves final content trailing whitespace so whitespace-specific rules can handle it:

def area(radius: float) -> float:
    """Return the area.

    The radius must be non-negative.  """

def area(radius: float) -> float:
    """Return the area.

    The radius must be non-negative.  
    """

Single-content-line docstrings are included when the literal itself spans multiple lines:

def area(radius: float) -> float:
    """
    Return the area."""

def area(radius: float) -> float:
    """
    Return the area.
    """

Parenthesized docstrings keep their aligned margin, and simple-suite docstrings use the configured generated indentation unit:

indent-width = 2

class Widget:
    (
        """Class summary.

        Class body."""
    )

def area(radius: float) -> float: """Return the area.
The radius must be non-negative."""; return 0.0

class Widget:
    (
        """Class summary.

        Class body.
        """
    )

def area(radius: float) -> float: """Return the area.
The radius must be non-negative.
  """; return 0.0

Tab indentation is used for generated simple-suite closing lines when configured:

indent-style = "tab"

def area(radius: float) -> float: """Return the area.
The radius must be non-negative."""; return 0.0

def area(radius: float) -> float: """Return the area.
The radius must be non-negative.
    """; return 0.0

Module, nested, decorated, async, and class docstrings each use the canonical margin for their own owner:

"""Module summary.

Module body."""

class Widget:
    @decorator
    async def render(self) -> None: """Method summary.
Method body."""; return None

    class Inner:
        """Class summary.

        Class body."""

"""Module summary.

Module body.
"""

class Widget:
    @decorator
    async def render(self) -> None: """Method summary.
Method body.
        """; return None

    class Inner:
        """Class summary.

        Class body.
        """

Quote delimiters, raw prefixes, and literal backslashes are preserved:

def path_hint() -> str:
    r'''Return C:\temp.
    Keep the path literal.'''

def path_hint() -> str:
    r'''Return C:\temp.
    Keep the path literal.
    '''

Already expanded docstrings, true one-line docstrings, blank-only docstrings, concatenated docstrings, multiline non-raw literals with escapes, and non-docstring strings are unchanged:

def already_expanded() -> None:
    """Summary.

    Body.
    """

def true_one_line() -> None:
    """Summary only."""

def blank_only() -> None:
    """  
    """

def concatenated() -> None:
    ("Summary.\n"
     "Body.")

def escaped_multiline() -> None:
    """Summary.\nBody."""

def not_docstring() -> None:
    value = 1
    """Summary.

    Body."""

Options¶

• indent-style: Indentation style used when generating the separate closing-quote line.
• indent-width: Indentation width used when generating the separate closing-quote line and measuring indentation.