regex - Match groups in Python

Question

Is there a way in Python to access match groups without explicitly creating a match object (or another way to beautify the example below)?

Here is an example to clarify my motivation for the question:

Following Perl code

if    ($statement =~ /I love (w+)/) {
  print "He loves $1
";
}
elsif ($statement =~ /Ich liebe (w+)/) {
  print "Er liebt $1
";
}
elsif ($statement =~ /Je t'aime (w+)/) {
  print "Il aime $1
";
}

translated into Python

m = re.search("I love (w+)", statement)
if m:
  print "He loves",m.group(1)
else:
  m = re.search("Ich liebe (w+)", statement)
  if m:
    print "Er liebt",m.group(1)
  else:
    m = re.search("Je t'aime (w+)", statement)
    if m:
      print "Il aime",m.group(1)

looks very awkward (if-else-cascade, match object creation).

Answer 1

You could create a little class that returns the boolean result of calling match, and retains the matched groups for subsequent retrieval:

import re

class REMatcher(object):
    def __init__(self, matchstring):
        self.matchstring = matchstring

    def match(self,regexp):
        self.rematch = re.match(regexp, self.matchstring)
        return bool(self.rematch)

    def group(self,i):
        return self.rematch.group(i)


for statement in ("I love Mary", 
                  "Ich liebe Margot", 
                  "Je t'aime Marie", 
                  "Te amo Maria"):

    m = REMatcher(statement)

    if m.match(r"I love (w+)"): 
        print "He loves",m.group(1) 

    elif m.match(r"Ich liebe (w+)"):
        print "Er liebt",m.group(1) 

    elif m.match(r"Je t'aime (w+)"):
        print "Il aime",m.group(1) 

    else: 
        print "???"

Update for Python 3 print as a function, and Python 3.8 assignment expressions - no need for a REMatcher class now:

import re

for statement in ("I love Mary",
                  "Ich liebe Margot",
                  "Je t'aime Marie",
                  "Te amo Maria"):

    if m := re.match(r"I love (w+)", statement):
        print("He loves", m.group(1))

    elif m := re.match(r"Ich liebe (w+)", statement):
        print("Er liebt", m.group(1))

    elif m := re.match(r"Je t'aime (w+)", statement):
        print("Il aime", m.group(1))

    else:
        print()