human
Here's a good function header given the following:
I wrote the below code

    if (sys.version_info >= (3,)):
        return
    if (sys.platform != 'win32'):
        return
    if hasattr(tempfile._candidate_tempdir_list, 'patched'):
        return
    unicode_error = False
    for var in ['TMPDIR', 'TEMP', 'TMP']:
        dir_ = os.getenv(var)
        if (not dir_):
            continue
        try:
            (dir_ + u'')
        except UnicodeDecodeError:
            unicode_error = True
            break
        if (dir_.find('?') != (-1)):
            unicode_error = True
            break
    if (not unicode_error):
        return
    kernel32 = ctypes.windll.kernel32
    kernel32.GetEnvironmentStringsW.argtypes = []
    kernel32.GetEnvironmentStringsW.restype = ctypes.c_void_p
    str_pointer = kernel32.GetEnvironmentStringsW()
    string = ctypes.wstring_at(str_pointer)
    env_vars = {}
    while (string != ''):
        if string[0].isalpha():
            (name, value) = string.split(u'=', 1)
            env_vars[name.encode('ascii')] = value
        str_pointer += ((len(string) + 1) * 2)
        string = ctypes.wstring_at(str_pointer)
    def _candidate_tempdir_list():
        dirlist = []
        for envname in ('TMPDIR', 'TEMP', 'TMP'):
            dirname = env_vars.get(envname)
            if dirname:
                dirlist.append(dirname)
        if (os.name == 'riscos'):
            dirname = os.getenv('Wimp$ScrapDir')
            if dirname:
                dirlist.append(dirname)
        elif (os.name == 'nt'):
            dirlist.extend(['c:\\temp', 'c:\\tmp', '\\temp', '\\tmp'])
        else:
            dirlist.extend(['/tmp', '/var/tmp', '/usr/tmp'])
        try:
            dirlist.append(os.getcwd())
        except (AttributeError, os.error):
            dirlist.append(os.curdir)
        return dirlist
    tempfile._candidate_tempdir_list = _candidate_tempdir_list
    setattr(tempfile._candidate_tempdir_list, 'patched', True)

What's a good function header?
assistant
#Here's a good function header.

def tempfile_unicode_patch():