Sunday, April 19, 2009

What's new in Py3k?

Recently, I have learned the programming language--Python. The knowledge based on Core PYTHON programming, but only the version of python before 2.5 is mentioned in this book. The official site encourage people who start projects using Py3K, so it is important to learn the Py3K by myself.
Py3K is backwards incompatible Python release. I list some tips (You can find more information on http://docs.python.org/3.0/whatsnew/3.0.html):
  • Print is Function
  It is a very famous change. The print statement is replaced with function print().
  • All text is Unicode
  That means you can no longer use the prefix 'u' in string such as u"...".
  • Integers
  1. long type is renamed to int. So there is only one built-in type of integers.
  2. int is a real 'natural' number, because Py3K removes the limit of int type.
  3. The form of octal literals changes.
There are some syntax changes base on PEP(http://www.python.org/dev/peps/).
PEP 0328, 3102, 3104, 3107, 3109, 3132, 3134, 3110, 3113, 3115.
Some changes are already taking effects in Python 2.6. And other changes can be found in official website http://docs.python.org/3.0/whatsnew/3.0.html.
The performance of Py3K is 10% slower than Python 2.5. But I think there is room for improvement.
Generally speaking, Py3K changes a lot.

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