percent-format-star-requires-sequence (F508)

Derived from the Pyflakes linter.

What it does

Checks for printf-style format strings that use the * specifier with non-tuple values.

Why is this bad?

The use of the * specifier with non-tuple values will raise a TypeError at runtime.

Example

from math import pi

"%(n).*f" % {"n": (2, pi)}

Use instead:

from math import pi

"%.*f" % (2, pi)  # 3.14

References

• Python documentation: printf-style String Formatting