Raw docstring #10998

[ShreySinha02]

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

[codespearhead]

@ShreySinha02 @KaniKim @Kludex , I'm afraid it's not clear to me which use case #10998 is meant to address, because changing the behavior of how a raw string is parsed would mean it's no longer being treated as a raw string.

Besides, as @dolfinus pointed out in that issue, which I encourage you to link to this PR btw, both the proposed fix and this one will act out if you mention C:\files\data in the description of the endpoint.

Either way, here's some data to help make you guys' explanations more clear.

Minimal Reproducible Example

1. Make sure you have Python 3, PIP 3 and virtualenv installed on your system:

python3 -V &&
pip3 -V &&
pip3 show virtualenv

2. Create a Python virtual environment and activate it:

python3 -m venv .venv &&
source .venv/bin/activate

3. Set up the demo:

pip install fastapi

4. Add the demo entrypoint and run it:

cat > main.py <<EOF && python main.py
from fastapi import FastAPI
from json import dump

app = FastAPI()

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

    Returns:
        Some integer.
    """
    return arg

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

    Returns:
        Some integer.
    """
    return arg

openapi_schema = app.openapi()
with open("openapi.json", "w") as file:
    dump(openapi_schema, file, indent=2)
EOF

Outputs

v0.110.1.json pr-11149.json

Git Diff

# git diff v0.110.1.json pr-11149.json

diff --git a/v0.110.1.json b/pr-11149.json
index f8d2a52..249b92b 100644
--- a/v0.110.1.json
+++ b/pr-11149.json
@@ -8,7 +8,7 @@
     "/foo": {
       "post": {
         "summary": "Foo",
-        "description": "Some function.\n\n\\f\n\nArgs:\n    arg: Some argument\n\nReturns:\n    Some integer.",
+        "description": "Some function.",
         "operationId": "foo_foo_post",
         "parameters": [
           {
@@ -50,7 +50,7 @@
     "/bar": {
       "post": {
         "summary": "Foo",
-        "description": "Some function. C:\\files\\data C:/files/data\n\n\\f\n\nArgs:\n    arg: Some argument\n\nReturns:\n    Some integer.",
+        "description": "Some function. C:",
         "operationId": "foo_bar_post",
         "parameters": [
           {