Raw docstring (leading `r`) defeats form feed `\f` truncation

[Kludex]

Discussed in https://github.com/tiangolo/fastapi/discussions/10531

^{Originally posted by jamesbraza October 26, 2023}

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Example Code

from fastapi import FastAPI

app = FastAPI()


@app.post("/lof")
def foo(arg: int = 5) -> int:
    """
    Some function.
    
    \f
    
    Args:
        arg: Some argument

    Returns:
        Some integer.
    """
    return arg

Description

Running ruff==0.1.3 on this, D301 will autofix to make the docstring be a raw string (lead by r).

@app.post("/lof")
def foo(arg: int = 5) -> int:
    r"""
    Some function.
    
    \f
    
    Args:
        arg: Some argument

    Returns:
        Some integer.
    """
    return arg

However, this breaks the form feed \f truncation from working, per https://fastapi.tiangolo.com/advanced/path-operation-advanced-configuration/#advanced-description-from-docstring

I think form feed \f truncation should still work even if the docstring is a raw string.

Operating System

macOS

Operating System Details

n/a

FastAPI Version

0.104.0

Pydantic Version

2.4.2

Python Version

3.11.5

Additional Context

No response

[KaniKim]

I little bit handled this by adding some code. I don't know what you actually want, but you want like this code situation?

Above code is with raw string that print to normal string. And also here is my code changed version.

Here is code about I write

[dolfinus]

Well, r"\f" =="\\f" != "\f"

With change you propose to docstrings like This endpoint saves data to C:\files\data will be truncated to This endpoint saves data to C:

[ShreySinha02]

opened the #11149 pr used codecs to convert rawstring so that it can be split on \f

  self.description = codecs.decode(self.description, "unicode_escape")