# Need a specific sort of string modification. Can someone help?

Nick Mellor thebalancepro at gmail.com
Mon Jan 7 04:40:02 CET 2013

```Hi Sia,

Find a multi-digit method in this version:

from string import maketrans
from itertools import takewhile

def is_digit(s): return s.isdigit()

class redux:

def __init__(self):
intab = '+-'
outtab = '  '
self.trantab = maketrans(intab, outtab)

def reduce_plusminus(self, s):
list_form = [r[int(r[0]) + 1:] if r[0].isdigit() else r
for r
in s.translate(self.trantab).split()]
return ''.join(list_form)

def reduce_plusminus_multi_digit(self, s):
spl = s.translate(self.trantab).split()
digits = [list(takewhile(is_digit, r))
for r
in spl]
numbers = [int(''.join(r)) if r else 0
for r
in digits]
skips = [len(dig) + num for dig, num in zip(digits, numbers)]
return ''.join([s[r:] for r, s in zip(skips, spl)])

if __name__ == "__main__":
p = redux()
print p.reduce_plusminus(".+3ACG.+5CAACG.+3ACG.+3ACG")
print p.reduce_plusminus("tA.-2AG.-2AG,-2ag")
print 'multi-digit...'
print p.reduce_plusminus_multi_digit(".+3ACG.+5CAACG.+3ACG.+3ACG")
print p.reduce_plusminus_multi_digit(".+12ACGACGACGACG.+5CAACG.+3ACG.+3ACG")

HTH,

Nick

On Saturday, 5 January 2013 19:35:26 UTC+11, Sia  wrote:
> I have strings such as:
>
>
>
> tA.-2AG.-2AG,-2ag
>
> or
>
> .+3ACG.+5CAACG.+3ACG.+3ACG
>
>
>
> The plus and minus signs are always followed by a number (say, i). I want python to find each single plus or minus, remove the sign, the number after it and remove i characters after that. So the two strings above become:
>
>
>
> tA..,
>
> and
>
> ...
>
>
>
> How can I do that?
>
> Thanks.

```