[Tutor] Regex not working as desired

[Alan Gauld]

On 27/02/18 09:50, Peter Otten wrote:
>> def all_digits(s):
>>     return all(c.isdigit() for c in s)
>  
> Note that isdigit() already checks all characters in the string:

Ah! I should have known that but forgot.
I think the singular name confused me.

> The only difference to your suggestion is how it handles the empty string:
> 
>>>> def all_digits(s):
> ...     return all(c.isdigit() for c in s)
> ... 
>>>> all_digits("")
> True
>>>> "".isdigit()
> False

Interesting, I'd have expected all() to return
False for an empty sequence... But looking at help(all)
it clearly states that it returns True. RTFM! :-(

However, in practice, and for this specific case, the
try/except route is probably best, I just wanted to
point out that there were other (concise) ways to
avoid a regex.


-- 
Alan G
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