On 9/16/2012 8:17 PM Steven D'Aprano said...
On 17/09/12 10:56, Scurvy Scott wrote:
Why would you use an underscore rather than a letter or name like I've
always seen. I've never seen an underscore used before.
An underscore on its own is often used to mean "don't care". Like a
scratch variable to hold a result when you don't actually need the result.
So in a for-loop:
for _ in range(20):
...
the idea is to tell the reader we don't actually care about the indexes
0, 1, 2, ... but only care that the loop happens 20 times.
Be sure you don't at some point depend on _ having a specific value
however, as return values of functions are given the _ name in the
absense of a designated label for the returned value:
ActivePython 2.6.6.15 (ActiveState Software Inc.) based on
Python 2.6.6 (r266:84292, Aug 24 2010, 16:01:11) [MSC v.1500 32 bit
(Intel)] on win32
Type "help", "copyright", "credits" or "license" for more information.
>>> def test(): return True
...
>>> _
Traceback (most recent call last):
File "<stdin>", line 1, in <module>
NameError: name '_' is not defined
>>> test()
True
>>> _
True
>>>
Emile
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