Question

So I get some input in python that I need to parse using regexps.

At the moment I’m using something like this:

matchOK = re.compile(r'^OK\s+(\w+)\s+(\w+)$')
matchFailed = re.compile(r'^FAILED\s(\w+)$')
#.... a bunch more regexps

for l in big_input:
  match = matchOK.search(l)
  if match:
     #do something with match
     continue
  match = matchFailed.search(l)
  if match:
     #do something with match
     continue
  #.... a bunch more of these 
  # Then some error handling if nothing matches

Now usually I love python because its nice and succinct. But this feels verbose. I’d expect to be able to do something like this:

for l in big_input:      
  if match = matchOK.search(l):
     #do something with match     
  elif match = matchFailed.search(l):
     #do something with match 
  #.... a bunch more of these
  else
    # error handling

Am I missing something, or is the first form as neat as I’m going to get?

Answer 1

class helper:
    def __call__(self, match):
        self.match= match
        return bool(match)

h= helper()
for l in big_input:      
    if h(matchOK.search(l)):
        # do something with h.match     
    elif h(matchFailed.search(l)):
        # do something with h.match 
    ... # a bunch more of these
    else:
        # error handling

Or matchers as class methods:

class matcher:
    def __init__(self):
        # compile matchers
        self.ok= ...
        self.failed= ...
        self....= ...

    def matchOK(self, l):
        self.match= self.ok(l)
        return bool(self.match)

    def matchFailed(self, l):
        self.match= self.failed(l)
        return bool(self.match)

    def match...(self, l):
        ...

m= matcher()
for l in big_input:      
    if m.matchOK(l):
        # do something with m.match     
    elif m.matchFailed(l):
        # do something with m.match 
    ... # a bunch more of these
    else:
        # error handling