what is this kind of string: b'string' ?

[Martin v. Loewis]

Am 04.09.2010 19:27, schrieb Stefan Behnel:
> Martin v. Loewis, 04.09.2010 18:52:
>> Am 01.09.2010 23:32, schrieb Stef Mientki:
>>>   in winpdb I see strings like this:
>>>
>>> >>> a = b'string'
>>> >>> a
>>> 'string'
>>> >>> type(a)
>>> <type 'str'>
>>>
>>> what's the "b" doing in front of the string ?
>>
>> It's redundant.
> 
> Not completely. (I know that you know this, but to those who don't, your
> answer may be misleading.)

Actually, I didn't think of this (knowing something and being aware of
it are different things ...)

I personally don't use it in the 2to3 way, because it requires Python
2.6. For code that needs to go back further, I typically do

  b('string')

with a custom b() function. That's less efficient, of course, since it
causes a function call on evaluation.

Thanks,
Martin