import timeit
from random import choice
from random import randrange
from string import uppercase

setup = """
class additive_identity(object):
 def __add__(self, other):
  return other

ai = additive_identity()

from random import choice
from random import randrange
from string import uppercase
strings = ["".join(choice(uppercase) for i in range(randrange(10))) for i in range(100)]"""

strings = ["".join(choice(uppercase) for i in range(randrange(10))) for i in range(100)]

print "SUM:", timeit.Timer("sum(strings, ai)", setup).repeat()
print "JOIN:", timeit.Timer("''.join(strings)", setup).repeat()
print "ADD:", timeit.Timer(" + ".join('"' + s + '"' for s in strings), "").repeat()