Migrating to Python2 to Python3

# py2
print "hello"

# py3
print("hello")

# py2
class X():
   def next():
      ...

# py3
class X():
   def __next__():
​      ...

d = {...}
# py2
for k,v in d.iteritems():
   ...

# py3
for k,v in d.items():
   ...