Fastest way to remove the first x characters from a very long string

[bruceg113355 at gmail.com]

On Saturday, May 16, 2015 at 9:46:17 AM UTC-4, Chris Angelico wrote:
> On Sat, May 16, 2015 at 11:28 PM,  <bruceg113355 at gmail.com> wrote:
> > I have a string that contains 10 million characters.
> >
> > The string is formatted as:
> >
> > "0000001 : some hexadecimal text ... \n
> > 0000002 : some hexadecimal text ... \n
> > 0000003 : some hexadecimal text ... \n
> > ...
> > 0100000 : some hexadecimal text ... \n
> > 0100001 : some hexadecimal text ... \n"
> >
> > and I need the string to look like:
> >
> > "some hexadecimal text ... \n
> > some hexadecimal text ... \n
> > some hexadecimal text ... \n
> > ...
> > some hexadecimal text ... \n
> > some hexadecimal text ... \n"
> >
> > I can split the string at the ":" then iterate through the list removing the first 8 characters then convert back to a string. This method works, but it takes too long to execute.
> >
> > Any tricks to remove the first n characters of each line in a string faster?
> 
> Given that your definition is "each line", what I'd advise is first
> splitting the string into lines, then changing each line, and then
> rejoining them into a single string.
> 
> lines = original_text.split("\n")
> new_text = "\n".join(line[8:] for line in lines)
> 
> Would that work?
> 
> ChrisA


Hi Chris,

I meant to say I can split the string at the \n.

Your approach using .join is what I was looking for.
Thank you,

Bruce