Can anybody explain the '-' in a 2-D creation code?

[André Roberge]

On Thursday, 25 June 2015 22:07:42 UTC-3, fl  wrote:
> Hi,
> 
> I read Ned's tutorial on Python. It is very interesting. On its last
> example, I cannot understand the '_' in:
> 
> 
> 
> board=[[0]*8 for _ in range(8)]
> 
> 
> I know  '_' is the precious answer, but it is still unclear what it is
> in the above line. Can you explain it to me?

'_' is the previous answer ONLY when using the read-eval-print-loop interpreter.

Here, it is the "name" of a variable; since we don't care about the particular name (it is used just for looping a fixed number of times), the common practice of using '_' has been used.  As you will have noted (since it confused you), '_' doesn't seem to designate anything of interest - unlike a variable name like 'string_index' or 'character', etc.

Sometimes, people will use the name "dummy" instead of '_', with the same idea in mind.
> 
> 
> Thanks,