no-blank-line-before-function-docstring (PDF204)¶

Part of the PDF rule category.

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Fix is always available.

Rule is incompatible with PDF205.

What it does¶

PDF204 removes blank lines immediately before function, method, and nested-function docstrings.

Only the adjacent blank-line run before the docstring statement is changed. Comments, decorators, function headers, and non-blank lines before the docstring are preserved. The rule applies to ordinary functions, async functions, methods, and nested functions. It does not apply to class docstrings, attribute docstrings, or simple-suite docstrings written on the same physical line as the function header.

Why is this useful?¶

Keeping a function docstring directly attached to the function body follows the default PEP 257 and Ruff style.

Ruff compatibility¶

This rule replaces Ruff's D201.

Examples¶

The canonical fix removes blank lines before a function docstring:

def function():

    """Docstring."""
    return None

def function():
    """Docstring."""
    return None

Nested functions and methods are handled independently, while class docstring spacing is left to class-specific rules:

class Client:

    """Class docstring."""

    def method(self):

        """Method docstring."""

        def nested():

            """Nested docstring."""
            return None

        return nested()

class Client:

    """Class docstring."""

    def method(self):
        """Method docstring."""

        def nested():
            """Nested docstring."""
            return None

        return nested()

Comments and decorators are preserved; only the adjacent blank run before the docstring is removed:

@decorator
async def function():
    # Leading comment.

    """Docstring."""
    return None

@decorator
async def function():
    # Leading comment.
    """Docstring."""
    return None

Simple-suite docstrings are ignored because there is no physical blank-line gap to normalize:

def function(): """Docstring."""; return None

Options¶

None.