ths, i misunderstood the method 

2015-03-11 1:33 GMT+08:00 Chris Angelico <rosuav@gmail.com>:
On Wed, Mar 11, 2015 at 4:27 AM, lou xiao <lox.xiao@gmail.com> wrote:
> I find a bug in str.lstrip, when i call str.lstrip, i get this result.
>
> tiny➜ ~ python
> Python 2.7.5+ (default, Feb 27 2014, 19:37:08)
> [GCC 4.8.1] on linux2
> Type "help", "copyright", "credits" or "license" for more information.
>>>> a='device_info'
>>>> a.lstrip('device')
> '_info'
>>>> a.lstrip('device_')
> 'nfo'
>>>>
> tiny➜ ~ uname -a
> Linux tinymint 3.11.0-12-generic #19-Ubuntu SMP Wed Oct 9 16:20:46 UTC 2013
> x86_64 x86_64 x86_64 GNU/Linux
> tiny➜ ~

It's not a bug, because it isn't doing what you think it is. It strips
a *set of characters*, not a prefix string.

https://docs.python.org/2/library/stdtypes.html#str.lstrip
https://docs.python.org/3/library/stdtypes.html#str.lstrip

ChrisA