Here's a puzzle...

[Bengt Richter]

On 21 Jul 2001 23:56:40 GMT, thedustbustr at aol.com (TheDustbustr) wrote:

>I'm trying to split the following string called data into four variables:
>
>:Angel PRIVMSG Wiz :here is my message!
>
>(so data=':Angel PRIVMSG Wiz :here is my message!') with an outcome of:
>
>sender='Angel'
>command='PRIVMSG'
>rcpt=Wiz'
>message='here is my message!'
>
>Unless my logic is flawed, this should return 'PRIVMSG':
>
>sender='Angel'
>print data[len(sender)+2:string.find(data[len(sender)+2:],' ')]
>
>It prints '' (an empty string).  Is my logic flawed, or does Python dislike a
>string splice determined by a function?
>
No, Python likes it fine ;-)

 >>> print data[len(sender)+2:string.find(data,' ',len(sender)+2)]
 PRIVMSG

Your string.find was giving you an offset from the beginning of the slice you
were passing it, not starting the search in data at a given offset.

When a big expression doesn't work, try the sub-expressions separately to see
if you're getting what you expect. Usually it will become clear ;-)

E.g., to see the slice (not splice ;-) parameters you were using you could
just change the ';' to a comma and drop the 'data' to print it out as a list:
 >>> print data[len(sender)+2:string.find(data[len(sender)+2:],' ')]

 >>> print     [len(sender)+2,string.find(data[len(sender)+2:],' ')]
 [7, 7]
so you were doing print data[7:7] and getting what you asked for ;-)

looking at what string.find was operating on:
 >>> data[len(sender)+2:]
 'PRIVMSG Wiz :here is my message!'
  01234567 -- guess where the second 7 in [7, 7] came from (not an offset into data)

>And if you are up to it, feel free to help me splice (correct terminology,
>parse?) for variables rcpt and message ;)
>
Not knowing the real grammar of your data string, here's a possibility:

 >>> data=':Angel PRIVMSG Wiz :here is my message!'
 >>> front,message = data.split(':')[1:]
 >>> sender,command,rcpt = front.split()
 >>>
 >>> sender
 'Angel'
 >>> command
 'PRIVMSG'
 >>> rcpt
 'Wiz'
 >>> message
 'here is my message!'


You could also do it with a regular expression.
The above rigidly depends on always having two colons and
always having three non-blank strings separated by white space
between the colons. (The [1:] throws away anything to the
left of the first colon).

For a better solution, post the detailed rules on the exact
character sequence in your data.