x= ["Dude", 'How is it going man', ' '] print x
['Dude', 'How is it going man', ' ']
j=[] for item in x:
... if re.search('\S+',item): ... j.append(item)
print j
['Dude', 'How is it going man']
What about: x= ["Dude", 'How is it going man', ' '] print [a for a in x if a.strip()]
Now, I first did that in a Perl script, but it easily comes across to Python. \S+ will usually mean 'one or more non-whitespace characters'. Brilliant for when your first Perl script accidentally appended \n to everything, even \n and \t. *embarassed*
Whereas, while I'm sure there is a string method that can do that, I'm not sure what it is.
Well the documentation on that is not sooo big ;-)
Also - say you have a list of words - j = " bag apple tomato cheese *marmite* sausages *scones*"
and you wanted to pick up each word that was asterisked. I did this as a string method then a regex.
try:
... indexes=[]
... lastIndex = 0
... while 1:
... x = j.index("*", lastIndex + 1)
... indexes.append(x)
... lastIndex = x
... except ValueError:
... pass
...
print indexes
[4, 10]
myString = j[5:10]
That gives me [25, 33, 45, 52], propably a C&P bug?
Now the regular expression -
x = re.finditer("\*(?P<myString>.*?)\*", j) a = x.next() print a.group('myString')
apple
Same error as above? And you said you want _all_ asteriksed words! How about this cute lil list comprehension: print [w for w in j.split() if words[0] == '*' and words[-1] == '*']
Now, while the regEx syntax is a big harsh to begin with, once you get the hang of it, it's OK, and the string method version I used felt too 'hacky' for me. Of course, both only work with pairs of asterisks, so I guess that makes them both hacky. : )
That's my 2c, I use string methods for stuff like that .startswith, .endswith, if 'foo' in x stuff is good as well. But sometimes, a regex is the
right tool for the job.
I didn't say that they are useless (and don't wanna troll or start a flameware), but IMHO they are a PITA when it comes to debugging. Ever touched a regexp after one year ;-)?
Regards,
Liam Clarke
Greetings, Wolfram
_______________________________________________ Tutor maillist - Tutor@python.org http://mail.python.org/mailman/listinfo/tutor
