Two improvements suggested by Greg Stein:

Two improvements suggested by Greg Stein:

PyString_FromFormatV(): In the final resize at the end, we can use
    PyString_AS_STRING() since we know the object is a string and can
    avoid the typechecking.

PyString_FromFormat(): GS sez: "For safety/propriety, you should call
    va_end() on the vargs variable."