Python 3.0 is here.

 

Guido and others released Python 3.0, a major "backward" incompatible python release.
It was a necessary choice to remove many old libraries, rework the std library, and change some behaviour.
You can see it all in What's new in Python 3.0.

  • The most visible change is maybe the print statement, print is now a function:
    print "toto"
    becomes 
    print("toto")
  • The % operator whis is supplented by the format() method:
    old: "Name: %s" % "john"
    new: "Name: {0}".format("john")
    old: "Names: %s %s" % ("John","Paul")
    new: "Names: {1} {0}".format("Paul","John")
    new named: "Names: {first_name} {family_name}".format(    family_name="Dububu", first_name="Jacky")

A 2to3 migration module could help you for this transition.