带有省略号_函数的python解释器？

Question

>>> type(_)
<type 'ellipsis'>

>>> 1 + 1
2
>>> _
2
>>> 

这个_函数有什么用处？

Answer 1

它只是让跟踪中间值或对之前返回的值进行操作变得更加容易。

>>> [x*x for x in range(5)]
[0, 1, 4, 9, 16]
>>> sum(_) # instead of having to type sum([0,1,4,9,16]) by hand
30