I think that concatenation with + is okay when you're concatenating two strings. And CPython can optimize x = x + y or x += y calls. http://docs.python.org/2/l

I think that concatenation with + is okay when you're concatenating two strings. And CPython can optimize x = x + y or x += y calls. http://docs.python.org/2/library/stdtypes.html http://docs.python.org/2/library/stdtypes.html