>[success] # 使用迭代器 ~~~ 1.iter 函數一個鮮為人知的特性是它接受一個可選的 callable 對象和一個標記(結尾)值作為輸入參數。當以這種方式使用的時候，它會創建一個迭代器， 這個迭代器會不斷調用 callable 對象直到返回值和標記值相等為止。 2.也就是說第一個參數必須是一個函數 def iter(source, sentinel=None): # known special case of iter """ iter(iterable) -> iterator iter(callable, sentinel) -> iterator Get an iterator from an object. In the first form, the argument must supply its own iterator, or be a sequence. In the second form, the callable is called until it returns the sentinel. """ pass ~~~ ~~~ CHUNKSIZE = 8192 def reader(s): while True: data = s.recv(CHUNKSIZE) if data == b'': break process_data(data) ~~~ * 可以寫成 ~~~ def reader2(s): for chunk in iter(lambda: s.recv(CHUNKSIZE), b''): pass # process_data(data) ~~~