Hızlı yanıt: kod örneği
Think of it this way:An iterator is just a fancy sounding term for an object that has a method. So a yield-ed function ends up being something like this:Original version:This is basically what the Python interpreter does with the above code:For more insight as to what's happening behind the scenes, the loop can be rewritten to this:Does that make more sense or just confuse you more? :)I should note that this is an oversimplification for illustrative purposes. :)
next()def some_function(): for i in xrange(4): yield ifor i in some_function(): print iclass it: def __init__(self): # Start at -1 so that we get 0 when we add 1 below. self.count = -1 # The __iter__ method will be called once by the 'for' loop. # The rest of the magic happens on the object returned by this method. # In this case it is the object itself. def __iter__(self): return self # The next method will be called repeatedly by the 'for' loop # until it raises StopIteration. def next(self): self.count += 1 if self.count < 4: return self.count else: # A StopIteration exception is raised # to signal that the iterator is done. # This is caught implicitly by the 'for' loop. raise StopIterationdef some_func(): return it()for i in some_func(): print iforiterator = some_func()try: while 1: print iterator.next()except StopIteration: pass