Python - “_” Argument to functions

In the interactive interpreter _ is used to reference the last returned value

Eg

>>> 2 + 4
6
>>> _ + 4
10

So you can use it as an argument in a function as well

>>> 2 + 4
6
>>> for i in range(_): print(i)
0
1
2
3
4
5

http://stackoverflow.com/questions/10232404/python-argument-to-functions