ruff/docs/rules/f-string-missing-placeholders.md

f-string-missing-placeholders (F541)

Derived from the Pyflakes linter.

Autofix is always available.

What it does

Checks for f-strings that do not contain any placeholder expressions.

Why is this bad?

F-strings are a convenient way to format strings, but they are not necessary if there are no placeholder expressions to format. In this case, a regular string should be used instead, as an f-string without placeholders can be confusing for readers, who may expect such a placeholder to be present.

An f-string without any placeholders could also indicate that the author forgot to add a placeholder expression.

Example

f"Hello, world!"

Use instead:

"Hello, world!"

References

• PEP 498