percent-format-invalid-format (F501)

Derived from the Pyflakes linter.

What it does

Checks for invalid printf-style format strings.

Why is this bad?

Conversion specifiers are required for printf-style format strings. These specifiers must contain a % character followed by a conversion type.

Example

"Hello, %" % "world"

Use instead:

"Hello, %s" % "world"

References

• Python documentation: printf-style String Formatting