> I didn't see a test case relating to the example in his comment, namely
>
> f.format("{0:{}}", 'foo', 5)
>
> Did I miss it?


The example should fail, which it wouldn't have done with the patch previously proposed. I believe the case is covered by the block:

    with self.assertRaises(ValueError):
        fmt.format("foo{1}{}", "bar", 6)

Though there is no harm in adding another test along the lines of:

    with self.assertRaises(ValueError):
        fmt.format("{0:{}}", "bar", 6)

If you think it is worthwhile?


I'm uncertain which documentation to update since the method which has had its signature updated is private and is called solely by Formatter.vformat .

Cheers,