On 4/06/2006 4:45 PM, Nexu wrote:
> On Sun, 2006-06-04 at 06:26 +0000, Marc Schoechlin wrote:
>> Hi !
>>
>> Nexu <[EMAIL PROTECTED]> schrieb:
>>> I'm trying to write a def to match a string that is an irc hostmask. eg:
>>> [EMAIL PROTECTED]
>>> But using re.search(). I get an error when the string starts with '*'.
>>> What is the best way to solve this?
>> I suppose the problem occurs because you expression is not a valid
>> regular expression.
>>
>> A correct regular expression should look like this:
>> "[EMAIL PROTECTED]"
> Thx for everyones input.
>
> This solved the problem:
> host = '[EMAIL PROTECTED]'
> mask = '[EMAIL PROTECTED]'
> newmask = re.sub('\*', '.*', re.sub('\?', '.', mask))
> result in that:
> re.search(newmask, host) == True
For a start, you must mean bool(re.search(newmask, host)) == True,
because re.search() returns a MatchObject or None; neither of those will
ever compare equal to True.
Moving right along, you have only one facet of your multi-faceted
multi-level problem fixed. Consider the following:
|>>> newmask
'[EMAIL PROTECTED]'
|>>> host = '[EMAIL PROTECTED]'
|>>> bool(re.search(newmask, host))
True
|>>> host2 = '[EMAIL PROTECTED]'
|>>> bool(re.search(newmask, host2))
True
|>>> host3 = '[EMAIL PROTECTED]'
|>>> bool(re.search(newmask, host3))
True
You didn't answer either of my questions that would have told me whether
host2 is a problem; if it is, you need a '$' at the end of newmask.
To fix the host3 problem, you need '\.' instead of '.'.
There is another possible host2-like problem: if you have a hostmask
that starts with 'one' (i.e. no '*' at the front), what you are doing
now will give True for incoming starting with 'anyone!' or
'I_am_the_one!' or whatever. I don't think you want that to happen. Two
solutions: (1) Put '^' at the start of newmask (2) use re.match()
instead of re.search().
Another question: should you be doing a case-insensitive match? If so,
you need re.search/match(newmask, host, re.IGNORECASE)
You may wish to consider looking at the fnmatch module, at three levels:
(1) calling fnmatch.fnmatchcase() may be good enough for your purpose
(2) you can use the undocumented fnmatch.translate(), like this:
newmask = fnmatch.translate(mask)
and use re.match()
(3) you can find the source code in
<YOUR_PYTHON_INSTALLATION_DIRECTORY>/Lib/fnmatch.py,
copy the translate function, and rip out the lines that treat '[' as
special.
HTH,
John
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