+
−class fireonce(object):
+
−    def __init__(self, func):
+
−        self.func = func
+
−    def __call__(self, *args, **kwargs):
+
−        if not self.func:
+
−            return None
+
−        retval = self.func(*args, **kwargs)
+
−        self.func = None
+
−
+
−@fireonce
+
−def foo(x):
+
−    print x
+
−    
+
−foo('bar')
+
−foo('fleem') # not printed