Regular expression question

[John Hunter]

>>>>> "jepler" == jepler  <jepler at unpythonic.net> writes:

    jepler> Anyway, here's an attempt at a Pythonic version of the
    jepler> perl code you posted.  Yes, it's longer than the Perl
    jepler> version.  

But it's also reusable.  I would make a minor modification.  Since you
are going to the trouble of writing a class, you may as well build the
dictionary for the user, since the dictionary can be built from a
sequence

import re

def whatever(v):
    return 'WhAtEvEr' + v

def want(v):
    return 'WaNt' + v


class translator:
    def __init__(self, allowed, variable):
        self._variable = variable
        #build a map of allowed names -> funcs from a list of funcs in allowed
        funcnames = map(lambda x: x.__name__, allowed)
        self.allowed = dict(zip(funcnames, allowed))

    def process(self, m):
        func = m.group(1).lower()
        return self.allowed[func](self._variable)

    def __call__(self, s):
        return re.sub('%%(.*?)%%', self.process, s)

x = translator( [whatever, want], variable='!' )

print x('I will do %%WHATEVER%%, you %%WANT%%')


Jonah, of course you would only need to bother with this class once.
Since you say you use this approach a lot, you can drop it into a
utils.py file and then just import it with

from utils import translator
# define your custom funcs
x = translator( [whatever, want], variable='!' )
print x('I will do %%WHATEVER%%, you %%WANT%%')

Which is short, clean, and fairly readable.  I came from perl to
python, and the main thing I didn't like about perl is you really had
to jump through some hoops do object oriented programming.  It's much
more natural in python, to me.

John Hunter