==============
Python 2 and 3
==============

**Python2.7**

.. code-block:: python

  print "hello"

::

  hello


**Python3.0**

.. code-block:: python

  print "hello"

::

    File "tmp.py", line 1
      print "hello"
                  ^
  SyntaxError: invalid syntax


**Python3.0**

.. code-block:: python

  print("hello")

::

  hello


**Python2.7**

.. code-block:: python

  print {}.keys()

::

  []


**Python3.0**

.. code-block:: python

  print({}.keys())

::

  <dict_keys object at 0x385f50>


**Python2.7**

.. code-block:: python

  print None < None

::

  False


**Python3.0**

.. code-block:: python

  print(None < None)

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      print(None < None)
  TypeError: unorderable types: NoneType() < NoneType()


**Python2.7**

.. code-block:: python

  print 1 / 2

::

  0


**Python3.0**

.. code-block:: python

  print(1 / 2)

::

  0.5


**Python2.7**

.. code-block:: python

  print 055

::

  45


**Python3.0**

.. code-block:: python

  print(055)

::

    File "tmp.py", line 1
      print(055)
              ^
  SyntaxError: invalid token


**Python3.0**

.. code-block:: python

  print(0o55)

::

  45


**Python2.7**

.. code-block:: python

  print long(987654321*987654321)

::

  975461057789971041


**Python3.0**

.. code-block:: python

  print(long(987654321*987654321))

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      print(long(987654321*987654321))
  NameError: name 'long' is not defined


**Python3.0**

.. code-block:: python

  print(int(987654321*987654321))

::

  975461057789971041


**Python2.7**

.. code-block:: python

  print u"\u0024"

::

  $


**Python3.0**

.. code-block:: python

  print(u"\u0024")

::

    File "tmp.py", line 1
      print(u"\u0024")
                    ^
  SyntaxError: invalid syntax


**Python3.0**

.. code-block:: python

  print("\u0024")

::

  $


**Python2.7**

.. code-block:: python

  if (isinstance("string", basestring)):
    print "True"

::

  True


**Python3.0**

.. code-block:: python

  if (isinstance("string", basestring)):
    print("True")

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      if (isinstance("string", basestring)):
  NameError: name 'basestring' is not defined


**Python3.0**

.. code-block:: python

  if (isinstance("string", str)):
    print("True")

::

  True


**Python2.7**

.. code-block:: python

  True = "True"

::

  (no output)


**Python3.0**

.. code-block:: python

  True = "True"

::

    File "tmp.py", line 1
      True = "True"
  SyntaxError: assignment to keyword


**Python2.7**

.. code-block:: python

  False = "False"

::

  (no output)


**Python3.0**

.. code-block:: python

  False = "False"

::

    File "tmp.py", line 1
      False = "False"
  SyntaxError: assignment to keyword


**Python2.7**

.. code-block:: python

  try:
    print 1+1
  except ValueError, err:
    print err 

::

  2


**Python3.0**

.. code-block:: python

  try:
    print(1+1)
  except ValueError, err:
    pass

::

    File "tmp.py", line 3
      except ValueError, err:
                       ^
  SyntaxError: invalid syntax


**Python3.0**

.. code-block:: python

  try:
    print(1+1)
  except ValueError as err:
    print(err)

::

  2


**Python2.7**

.. code-block:: python

  print [x for x in 1, 2, 3]

::

  [1, 2, 3]


**Python3.0**

.. code-block:: python

  print([x for x in 1, 2, 3])

::

    File "tmp.py", line 1
      print([x for x in 1, 2, 3])
                         ^
  SyntaxError: invalid syntax


**Python3.0**

.. code-block:: python

  print([x for x in (1, 2, 3)])

::

  [1, 2, 3]


**Python2.7**

.. code-block:: python

  print ''.join([`x` for x in (1,2,3)])

::

  123


**Python3.0**

.. code-block:: python

  print(''.join([`x` for x in (1,2,3)]))

::

    File "tmp.py", line 1
      print(''.join([`x` for x in (1,2,3)]))
                     ^
  SyntaxError: invalid syntax


**Python3.0**

.. code-block:: python

  print(''.join([repr(x) for x in (1,2,3)]))

::

  123


**Python2.7**

.. code-block:: python

  print 1 <> 2

::

  True


**Python3.0**

.. code-block:: python

  print(1 <> 2)

::

    File "tmp.py", line 1
      print(1 <> 2)
               ^
  SyntaxError: invalid syntax


**Python3.0**

.. code-block:: python

  print(1 != 2)

::

  True


**Python2.7**

.. code-block:: python

  exec = "exec"

::

    File "tmp.py", line 1
      exec = "exec"
           ^
  SyntaxError: invalid syntax


**Python3.0**

.. code-block:: python

  exec = "exec"

::

  (no output)


**Python2.7**

.. code-block:: python

  print buffer("Hello world")

::

  Hello world


**Python3.0**

.. code-block:: python

  print(buffer("Hello world", 6, 5))

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      print(buffer("Hello world", 6, 5))
  NameError: name 'buffer' is not defined


**Python3.0**

.. code-block:: python

  print(repr(memoryview(b"Hello world")))

::

  <memory at 0x3c3660>


**Python2.7**

.. code-block:: python

  print {"a":1}.has_key("a")

::

  True


**Python3.0**

.. code-block:: python

  print({"a":1}.has_key("a"))

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      print({"a":1}.has_key("a"))
  AttributeError: 'dict' object has no attribute 'has_key'


**Python3.0**

.. code-block:: python

  print("a" in {"a":1})

::

  True


**Python3.0**

.. code-block:: python

  import _winreg

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      import _winreg
  ImportError: No module named _winreg


**Python2.7**

.. code-block:: python

  import ConfigParser

::

  (no output)


**Python3.0**

.. code-block:: python

  import ConfigParser

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      import ConfigParser
  ImportError: No module named ConfigParser


**Python3.0**

.. code-block:: python

  import configparser

::

  (no output)


**Python2.7**

.. code-block:: python

  import copy_reg

::

  (no output)


**Python3.0**

.. code-block:: python

  import copy_reg

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      import copy_reg
  ImportError: No module named copy_reg


**Python3.0**

.. code-block:: python

  import copyreg

::

  (no output)


**Python2.7**

.. code-block:: python

  import Queue

::

  (no output)


**Python3.0**

.. code-block:: python

  import Queue

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      import Queue
  ImportError: No module named Queue


**Python3.0**

.. code-block:: python

  import queue

::

  (no output)


**Python2.7**

.. code-block:: python

  import SocketServer

::

  (no output)


**Python3.0**

.. code-block:: python

  import SocketServer

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      import SocketServer
  ImportError: No module named SocketServer


**Python3.0**

.. code-block:: python

  import socketserver

::

  (no output)


**Python2.7**

.. code-block:: python

  import markupbase

::

  (no output)


**Python3.0**

.. code-block:: python

  import markupbase

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      import markupbase
  ImportError: No module named markupbase


**Python3.0**

.. code-block:: python

  import _markupbase

::

  (no output)


**Python2.7**

.. code-block:: python

  import repr

::

  (no output)


**Python3.0**

.. code-block:: python

  import repr

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      import repr
  ImportError: No module named repr


**Python3.0**

.. code-block:: python

  import reprlib

::

  (no output)


**Python2.7**

.. code-block:: python

  import test.test_support

::

  (no output)


**Python3.0**

.. code-block:: python

  import test.test_support

::

  Traceback (most recent call last):
    File "tmp.py", line 1, in <module>
      import test.test_support
  ImportError: No module named test_support


**Python3.0**

.. code-block:: python

  import test.support

::

  (no output)


**Python2.7**

.. code-block:: python

  import string
  print string.letters

::

  abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ


**Python3.0**

.. code-block:: python

  import string
  string.letters

::

  Traceback (most recent call last):
    File "tmp.py", line 2, in <module>
      string.letters
  AttributeError: 'module' object has no attribute 'letters'


**Python3.0**

.. code-block:: python

  import string
  print(string.ascii_letters)

::

  abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ


**Python2.7**

.. code-block:: python

  import string
  print string.uppercase

::

  ABCDEFGHIJKLMNOPQRSTUVWXYZ


**Python3.0**

.. code-block:: python

  import string
  string.uppercase

::

  Traceback (most recent call last):
    File "tmp.py", line 2, in <module>
      string.uppercase
  AttributeError: 'module' object has no attribute 'uppercase'


**Python3.0**

.. code-block:: python

  import string
  print(string.ascii_uppercase)

::

  ABCDEFGHIJKLMNOPQRSTUVWXYZ


**Python2.7**

.. code-block:: python

  import string
  print string.lowercase

::

  abcdefghijklmnopqrstuvwxyz


**Python3.0**

.. code-block:: python

  import string
  string.lowercase

::

  Traceback (most recent call last):
    File "tmp.py", line 2, in <module>
      string.lowercase
  AttributeError: 'module' object has no attribute 'lowercase'


**Python3.0**

.. code-block:: python

  import string
  print(string.ascii_lowercase)

::

  abcdefghijklmnopqrstuvwxyz