human
I wrote the below code

    def isclass(obj):
        return (isinstance(obj, class_type_) or hasattr(obj, '__bases__'))
    opener = OpenerDirector()
    default_classes = [ProxyHandler, UnknownHandler, HTTPHandler, HTTPDefaultErrorHandler, HTTPRedirectHandler, FTPHandler, FileHandler, HTTPErrorProcessor]
    check_classes = list(default_classes)
    check_classes.append(HTTPSContextHandler)
    skip = []
    for klass in check_classes:
        for check in handlers:
            if isclass(check):
                if issubclass(check, klass):
                    skip.append(klass)
            elif isinstance(check, klass):
                skip.append(klass)
    for klass in default_classes:
        if (klass not in skip):
            opener.add_handler(klass())
    ssl_context = kw.get('ssl_context')
    if (HTTPSContextHandler not in skip):
        opener.add_handler(HTTPSContextHandler(ssl_context))
    for h in handlers:
        if isclass(h):
            h = h()
        opener.add_handler(h)
    return opener

What's a good function header?

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

def build_opener(*handlers, **kw):