[Tutor] To get numeric prefix in a string if present

[Alan Gauld]

On 04/05/2021 05:03, Manprit Singh wrote:
> Dear sir ,
> Consider the problem of getting numeric prefix in a string if present.
> 
> st = "23fgh"
> st1 = ""
> for ele in st:
>     if ele.isdigit():
>         st1 += ele
>     else:
>         break
> print(st1 or "Numeric prefix not in string" )
> 
> Here st variable contains the string from which the numeric prefix has to
> be retrieved, which is 23 . The code written above gives the right answer.
> 
> My major question is - The way I have used break statement  with else  is
> correct ?

Only commenting on the else part - yes, it is correct.
My only comment would be that I prefer to have the break in the first
clause so that it is easier to spot (if you have a lot of code in the
processing section which is not the case here) So I'd write it as:

for ele in st:
    if not ele.isdigit():
       break
    else:
       st1 += ele


But that really only matters if the other block is long, in
which case the break can "get lost"  in among the other code.

-- 
Alan G
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