"""Word completion for GNU readline 2.0. This requires the latest extension to the readline module. The completercompletes keywords, built-ins and globals in a selectable namespace (whichdefaults to __main__); when completing NAME.NAME..., it evaluates (!) theexpression up to the last dot and completes its attributes. It's very cool to do "import sys" type "sys.", hit thecompletion key (twice), and see the list of names defined by thesys module! Tip: to use the tab key as the completion key, call     readline.parse_and_bind("tab: complete") Notes: - Exceptions raised by the completer function are *ignored* (andgenerally cause the completion to fail).  This is a feature -- sincereadline sets the tty device in raw (or cbreak) mode, printing atraceback wouldn't work well without some complicated hoopla to save,reset and restore the tty state. - The evaluation of the NAME.NAME... form may cause arbitraryapplication defined code to be executed if an object with a__getattr__ hook is found.  Since it is the responsibility of theapplication (or the user) to enable this feature, I consider this anacceptable risk.  More complicated expressions (e.g. function calls orindexing operations) are *not* evaluated. - GNU readline is also used by the built-in functions input() andraw_input(), and thus these also benefit/suffer from the completerfeatures.  Clearly an interactive application can benefit byspecifying its own completer function and using raw_input() for allits input. - When the original stdin is not a tty device, GNU readline is neverused, and this module (and the readline module) are silently inactive. """ import __builtin__import __main__ __all__ = ["Completer"] class Completer:    def __init__(self, namespace = None):        """Create a new completer for the command line.         Completer([namespace]) -> completer instance.         If unspecified, the default namespace where completions are performed        is __main__ (technically, __main__.__dict__). Namespaces should be        given as dictionaries.         Completer instances should be used as the completion mechanism of        readline via the set_completer() call:         readline.set_completer(Completer(my_namespace).complete)        """         if namespace and not isinstance(namespace, dict):            raise TypeError,'namespace must be a dictionary'         # Don't bind to namespace quite yet, but flag whether the user wants a        # specific namespace or to use __main__.__dict__. This will allow us        # to bind to __main__.__dict__ at completion time, not now.        if namespace is None:            self.use_main_ns = 1        else:            self.use_main_ns = 0            self.namespace = namespace     def complete(self, text, state):        """Return the next possible completion for 'text'.         This is called successively with state == 0, 1, 2, ... until it        returns None.  The completion should begin with 'text'.         """        if self.use_main_ns:            self.namespace = __main__.__dict__         if state == 0:            if "." in text:                self.matches = self.attr_matches(text)            else:                self.matches = self.global_matches(text)        try:            return self.matches[state]        except IndexError:            return None     def global_matches(self, text):        """Compute matches when text is a simple name.         Return a list of all keywords, built-in functions and names currently        defined in self.namespace that match.         """        import keyword        matches = []        n = len(text)        for list in [keyword.kwlist,                     __builtin__.__dict__,                     self.namespace]:            for word in list:                if word[:n] == text and word != "__builtins__":                    matches.append(word)        return matches     def attr_matches(self, text):        """Compute matches when text contains a dot.         Assuming the text is of the form NAME.NAME....[NAME], and is        evaluatable in self.namespace, it will be evaluated and its attributes        (as revealed by dir()) are used as possible completions.  (For class        instances, class members are also considered.)         WARNING: this can still invoke arbitrary C code, if an object        with a __getattr__ hook is evaluated.         """        import re        m = re.match(r"(\w+(\.\w+)*)\.(\w*)", text)        if not m:            return        expr, attr = m.group(1, 3)        object = eval(expr, self.namespace)        words = dir(object)        if hasattr(object,'__class__'):            words.append('__class__')            words = words + get_class_members(object.__class__)        matches = []        n = len(attr)        for word in words:            if word[:n] == attr and word != "__builtins__":                matches.append("%s.%s" % (expr, word))        return matches def get_class_members(klass):    ret = dir(klass)    if hasattr(klass,'__bases__'):        for base in klass.__bases__:            ret = ret + get_class_members(base)    return ret try:    import readlineexcept ImportError:    passelse:    readline.set_completer(Completer().complete)