Re: OT: Python help

[Carsten Dominik <dominik@uva.nl>]

On Jul 20, 2010, at 3:08 PM, Peter Westlake wrote:

>
>
> On Tue, 20 Jul 2010 16:58 +0530, "Puneeth" <punchagan@gmail.com>  
> wrote:
>> On Tue, Jul 20, 2010 at 4:50 PM, Puneeth <punchagan@gmail.com> wrote:
>>> On Tue, Jul 20, 2010 at 4:43 PM, Carsten Dominik <dominik@uva.nl>  
>>> wrote:
>>>> Please show me the full line of code, I am currently editing a  
>>>> python script
>>>> without any knowledge of python...
>>>
>>> my_string = "Hello\nWorld"
>>> my_new_string = my_string.replace("\n", "\n> ")
>>
>> Sorry, this code (obviously) doesn't prepend ">" to the first line
>> Add this line to do that.
>>
>> my_new_string = "> " + my_new_string
>
> Here's a Pythonic way to do it, tested:
>
>  import re
>
>  my_string = "Hello\nWorld"
>  pattern = re.compile('^',re.MULTILINE)
>  my_new_string = re.sub(pattern, '> ', my_string)
>
> This still might not be quite right, as it will turn "Hello\nWorld\n"
> into "> Hello\n> World\n> ". Avoid that by using a negative lookahead
> for the end of the string:
>
>  my_string = "Hello\n\nWorld\n"
>  pattern = re.compile('^(?!\Z)',re.MULTILINE)
>  my_new_string = re.sub(pattern, '> ', my_string)
>  print my_new_string
>
> gives:
>
>> Hello
>>
>> World
>
>
> Peter.


Great.  I learned something today.  Thanks!

- Carsten


- Carsten