On 05/01/2013 10:35, 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.
Here is a naive solution (I am sure there are more elegant ones) -
def strip(old_string):
new_string = ''
max = len(old_string)
pos = 0
while pos < max:
char = old_string[pos]
if char in ('-', '+'):
num_pos = pos+1
num_str = ''
while old_string[num_pos].isdigit():
num_str += old_string[num_pos]
num_pos += 1
pos = num_pos + int(num_str)
else:
new_string += old_string[pos]
pos += 1
return new_string
It caters for the possibility that the number following the +/- could be
greater than 9 - I don't know if you need that.
It works with your examples, except that the second one returns '....',
which I think is correct - there are 4 dots in the original string.
HTH
Frank Millman
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