python運行錯誤及解決——AttributeError: 'generator' object has no attribute '_next_'

>>> a=(x*3 for x in range(5))
>>> a._next_()
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'generator' object has no attribute '_next_'

運行時出現上述錯誤，以爲是python版本問題，結果發現：
next前後的"_"是兩個連用

錯誤： _next_()
正確：__next__()

>>> a=(x*3 for x in range(5))
>>> a.__next__()
0
>>> a.__next__()
3

ok