human
I wrote the below code

    def is_module_for_sure(mod, search_path=sys.path):
        mod = mod.replace('(', '')
        try:
            mod_name = mod
            while ('.' in mod_name):
                (pack_name, _sep, mod_name) = mod.partition('.')
                (f, p, d) = imp.find_module(pack_name, search_path)
                search_path = [p]
            imp.find_module(mod_name, search_path)
        except ImportError:
            try:
                module = __import__(mod)
            except ImportError as exc:
                missing = str(exc).split()[(-1)]
                if ((missing != mod.split('.')[(-1)]) or ('cannot    import' in str(exc))):
                    _missingImport.add(missing)
                    return True
                return False
            except Exception as exc:
                traceback.print_exc()
                return False
        return True
    def is_module(mod):
        'Checks    for    non    module    imports.'
        if (mod in modules_cache):
            return modules_cache[mod]
        res = is_module_for_sure(mod)
        modules_cache[mod] = res
        return res
    current_path = os.path.dirname(pep8.current_file)
    current_mod = os.path.basename(pep8.current_file)
    if (current_mod[(-3):] == '.py'):
        current_mod = current_mod[:(-3)]
    split_line = logical_line.split()
    split_line_len = len(split_line)
    if ((split_line[0] in ('import', 'from')) and (split_line_len > 1) and (not is_import_exception(split_line[1]))):
        pos = logical_line.find(',')
        if (pos != (-1)):
            if (split_line[0] == 'from'):
                (yield (pos, 'N301:    one    import    per    line'))
            return
        pos = logical_line.find('*')
        if (pos != (-1)):
            (yield (pos, 'N303:    No    wildcard    (*)    import.'))
            return
        if ((split_line_len in (2, 4, 6)) and (split_line[1] != '__future__')):
            if (('from' == split_line[0]) and (split_line_len > 3)):
                mod =...

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

def nova_import_rules(logical_line):