\s doesn't match

[Lloyd Zusman]

<r at dslsubc13.ultracom.net> writes:

> I did this:
> 
> a = 'a b'
> if match(r'\s',a): print 'error'
> 
> and it didn't match.
> 
> a = ' b'
> 
> and it did match. Documentation seems to imply that \s matches
> whitespace anywhere in the string, what gives?

The `match' method matches characters anchored at the *beginning* of
the string.  What follows is the first part of the documentation for
`match' ..

  match (pattern, string) 
        Return how many characters at the beginning of string match the
        regular expression pattern.  [ ... ]

If you want to match for a pattern anywhere in the string, you should
use `search' and not `match', as follows ...

  a = 'a b'
  if search(r'\s',a): print 'error'

In other words, the `match' method works as if a `search' is being
done with an implied `^' character as the leftmost character of the
pattern ...

   match(r'\s',a)    is equivalent to     search(r'^\s',a)

I hope this helps.

-- 
 Lloyd Zusman
 ljz at asfast.com