[Tutor] Detect duplicate digits in a number

[Joel Goldstick]

On Tue, Feb 8, 2022 at 8:46 PM Joel Goldstick <joel.goldstick at gmail.com> wrote:
>
> On Tue, Feb 8, 2022 at 8:39 PM Manprit Singh <manpritsinghece at gmail.com> wrote:
> >
> > Dear Sir,
> >
> > I have to produce a result False if a number contains repeating digits and
> > True if the number do not have any repeating digit:
> >
> > Example :
> > if number is 2343 the result produced must be False
> > if number is 235 the result produced must be True
> >
> > I have tried to implement it in  the following ways:
> > 1) Using user defined function
> >
> > def detect_repeat(num):
> >     lx = []
> >     while num:
> >         num, rem = divmod(num, 10)
> >         if rem  in lx:
> >             return False
> >         lx.append(rem)
> >     return True
> >
> > ans = detect_repeat(2343)
> > print(ans)   # Results in False that is the desired result
> >
> > 2) Using str, set, len
> >
> > len(set(str(2343))) == len(str(2343))
> > that also produces the  desired result -False
> >
> > The second solution according to me lacks readability and again there are
> > lots of conversion str, set and all .
> > The  first solution, I feel , is good.
> >
> > Just need your opinion and guidance . In the first solution If you can see,
> > there are two return statements . Is this practice considered ok ?
> >
> > Regards
> > Manprit Singh
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>
> You can convert your number to a string.  Then convert the string to a
> list of characters.  Then convert the list to a set.  If the length of
> the set is different than the length of the list, you have repeated
> digits:
>
> >>> n = 12341
> >>> s = str(n)
> >>> s
> '12341'
> >>> l = list(s)
> >>> l
> ['1', '2', '3', '4', '1']
> >>> s = set(l)
> >>> s
> {'4', '2', '3', '1'}
> >>> len(s)
> 4
> >>> len(l)
> 5

> Joel Goldstick

Sorry, I was too quick to read your original post, so I offered a
solution you already know about.  I think the manipulation of the data
into different data types is more clear(to me!).  Maybe it's also more
'pythonic' in that it makes use of python features.

-- 
Joel Goldstick