Pattern Matching Given # of Characters and no String Input; use RegularExpressions?

[Synonymous]

tiissa <tiissa at nonfree.fr> wrote in message news:<426403c7$0$773$626a14ce at news.free.fr>...
> Synonymous wrote:
> > tiissa <tiissa at nonfree.fr> wrote in message news:<42623ba8$0$10322$636a15ce at news.free.fr>...
> > 
> >>tiissa wrote:
> >>
> >>>If you know the number of characters to match can't you just compare 
> >>>slices?
> >>
> >>If you don't, you can still do it by hand:
> >>
> >>In [7]: def cmp(s1,s2):
> >>   ....:     diff_map=[chr(s1[i]!=s2[i]) for i in range(min(len(s1), 
> >>len(s2)))]
> >>   ....:     diff_index=''.join(diff_map).find(chr(True))
> >>   ....:     if -1==diff_index:
> >>   ....:         return min(len(s1), len(s2))
> >>   ....:     else:
> >>   ....:         return diff_index
> >>   ....:
> > 
> > I will look at that, although if i have 300 images i dont want to type
> > all the comparisons (In [9]: cmp('ccc','cccap')) by hand, it would
> > just be easier to sort them then :).
> 
> I didn't meant you had to type it by hand. I thought about writing a 
> small script (as opposed to using some in the standard tools). It might 
> look like:
> 
> In [22]: def make_group(L):
>     ....:     root,res='',[]
>     ....:     for i in range(1,len(L)):
>     ....:         if ''==root:
>     ....:             root=L[i][:cmp(L[i-1],L[i])]
>     ....:             if ''==root:
>     ....:                 res.append((L[i-1],[L[i-1]]))
>     ....:             else:
>     ....:                 res.append((root,[L[i-1],L[i]]))
>     ....:         elif len(root)==cmp(root,L[i]):
>     ....:             res[-1][1].append(L[i])
>     ....:         else:
>     ....:             root=''
>     ....:     if ''==root:
>     ....:         res.append((L[-1],[L[-1]]))
>     ....:     return res
>     ....:
> 
> In [23]: L=['cccat','cccap','cccan','dddfa','dddfg','dddfz']
> 
> In [24]: L.sort()
> 
> In [25]: make_group(L)
> Out[25]: [('ccca', ['cccan', 'cccap', 'cccat']), ('dddf', ['dddfa', 
> 'dddfg', 'dddfz'])]
> 
> 
> However I guarantee no optimality in the number of classes (but, hey, 
> that's when you don't specify the size of the prefix).
> (Actually, I guarantee nothing at all ;p)
> But in particular, you can have some file singled out:
> 
> In [26]: make_group(['cccan','cccap','cccat','cccb'])
> Out[26]: [('ccca', ['cccan', 'cccap', 'cccat']), ('cccb', ['cccb'])]
> 
> 
> It is a matter of choice: either you want to specify by hand the size of 
> the prefix and you'd rather look at itertools as pointed out by Kent, or 
> you don't and a variation with the above code might do the job.

Thank you, that is very kool I found out how to copy files finally
with shutil too, so i'm getting close to doing something.  Going to be
working on an old computer, playing with files = dangerous lol.

Thanks for your help and taking the time to post! 

Bye :o)

S M