Newbie question - what is the 'r' operator?

[Thomas A. Bryan]

Craig Findlay wrote:
> 
> This is probably obvious but ...
> 
> I have seen example code where an 'r' prefix is used in from of a
> string, eg r'mystring'
> 
> What does it do, I can't seem to locate any documentation about it.
> Thanks in advance for any help.

It indicates a raw string.

>>> s1 = 'a \normal \tstring\012example' 
>>> print s1
a 
ormal   string
example
>>> s2 = r'a \normal \tstring\012example' 
>>> print s2
a \normal \tstring\012example

I'm not sure of the formal definition of a raw string.  It may 
simply escape all of the backslashes.  For example, 

>>> s1
'a \012ormal \011string\012example'
>>> s2
'a \\normal \\tstring\\012example'

Thus, \t won't be interpreted as a tab in a raw string.

great-for-regular-expressions-and-win32-paths-ly yours
---Tom