pywin32: EnumFontFamilies breaks python

To wit:

import win32gui
def enum_fonts(typeface=None):
    hwnd = win32gui.GetDesktopWindow()
    dc = win32gui.GetWindowDC(hwnd)

    res = []
    def callback(*args):
        res.append(args)
    win32gui.EnumFontFamilies(dc, typeface, callback)

    win32gui.ReleaseDC(hwnd, dc)
    return res

res = enum_fonts()
for r in res:
    print r[0].lfF开发者_StackOverflow中文版aceName

What follows is a bizarre aberration:

System
Terminal
Fixedsys
Roman
Script
Modern
Small Fonts
MS Serif
WST_Czec
WST_Engl
WST_Fren
WST_Germ
WST_Ital
WST_Span
WST_Swed
Courier
MS Sans Serif
Marlett
Arial
...
Waker
TT Anvers Black
TT Anvers
wodSymbols
Traceback (most recent call last):
  File "test.py", line 48, in <module>
    for r in res:
TypeError: an integer is required

It broke python!

Am I making an incorrect assumption with the way I'm calling the function? Is this a known bug in pywin32? Is there any other way to enumerate font families from python?

Ah I will shoot myself. The callback has to return an integer - 0 to stop iterating, non-zero to continue. This works fine:

def enum_fonts(typeface=None):
    hwnd = win32gui.GetDesktopWindow()
    dc = win32gui.GetWindowDC(hwnd)

    res = []
    def callback(*args):
        res.append(args)
        return 1
    win32gui.EnumFontFamilies(dc, typeface, callback)

    win32gui.ReleaseDC(hwnd, dc)
    return res