Hi Mark!

In general the patch is fine but it has some small issues.

* Your patches are all reversed. They remove (-) the new lines instead
of adding (+) them. Why aren't you using svn diff > file.patch?
* You are mixing tabs with spaces. All 2.6 C files and most 3.0 C files
are still using tabs.
* You forgot about %f. For large values the format characters f and F
are using the exponent display, too "%f" % 1e60 == '1e+60'
* You cannot assume that char is unsigned. Use Py_CHARMAP(char) instead.
I think that you can make the code more readable when you do format_char
= tolower(Py_CHARMAP(format_char)); first.
* The code is not C89 conform. The standards dictate that you cannot
declare a var in the middle of a block. New var must be declared right
after the {