How to noqa E501 in docstring?

[jamesbraza]

Here is some Python code with a Google-style docstring, containing a Mermaid diagram rendered by Sphinx:

def foo() -> None:
    """
    Some Google-style docstring.

    # ruff: noqa: E501

    .. mermaid::

       flowchart TD
           A([Start]) --> B["`Apples Apples Apples Apples Apples Apples Apples Apples Apples Apples Apples`"]
    """

The last line is designed to trigger E501. Currently with ruff==0.0.286:

> ruff --isolated --select=E501 --line-length=88 a.py
a.py:10:98: E501 Line too long (109 > 88 characters)
Found 1 error.

How can I E501:

• Just this docstring
• Without adding a comment to the flowchart source line?

[charliermarsh]

Can you try adding the noqa just after the closing triple-quotes?

[jamesbraza]

def foo() -> None:
    """  # ruff: noqa: E501
    Some Google-style docstring.

    .. mermaid::

       flowchart TD
           A([Start]) --> B["`Apples Apples Apples Apples Apples Apples Apples Apples Apples Apples Apples`"]
    """  # ruff: noqa: E501

Trying either end of the triple quotes doesn't properly disable the E501, and using the 2nd triple quote also leads to a warning:

> ruff --isolated --select=E501 --line-length=88 a.py
warning: Unexpected `# ruff: noqa` directive at a.py:9. File-level suppression comments must appear on their own line.
a.py:8:98: E501 Line too long (109 > 88 characters)
Found 1 error.

[zanieb]

If you do

def foo() -> None:
    """
    Some Google-style docstring.

    .. mermaid::

       flowchart TD
           A([Start]) --> B["`Apples Apples Apples Apples Apples Apples Apples Apples Apples Apples Apples`"]
    """  # noqa: E501

it will work. ruff: noqa is for file-level suppression and shouldn't be used for suppressing a single item — which is why you get that warning.

[jamesbraza]

Ah that is what I needed, thank you!

I think this # noqa after the docstring is worth adding to the docs: https://beta.ruff.rs/docs/tutorial/#ignoring-errors

I can contribute something

[charliermarsh]

It’s mentioned here, but not in the tutorial: https://beta.ruff.rs/docs/configuration/#error-suppression

[jamesbraza]

Oh I opened a PR, but seeing that section, I can make it better in the morning.

[jamesbraza]

Alright, updated the PR to link the tutorial to the error suppression docs 👌