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Python

Posted by Ben Junya
Ben Junya
12,365 Points

What are the differences between python 2.7 and 3.0?

I'm being forced to use python 2.7 in Google App Engine (GAE). I was just curious what the differences in 2.7 to 3.0 are.

I'm also curious if the Treehouse lessons here will be applicable to what i'm doing. Anyone know? Thanks in advance!

Ben

3 Answers

Ron Fisher
Ron Fisher
5,752 Points
Ron Fisher
Ron Fisher
5,752 Points

Ben,

The differences between Python 2.7 and 3.? are well documented. The concepts of linear code, all the way through the Object Oriented code are the same in both version. If you study the few commands that are different in the 2 version, such as the input/print and others, then you should have no problems switching between the versions. You can also put tests to find the version (sys.version) and then make code to work in both versions.

Ron

Stone Preston
Stone Preston
42,016 Points
Stone Preston
Stone Preston
42,016 Points

here is an article that outlines the key differences between the 2

here is a wiki page from the python wiki that covers some differences as well

Ben Junya
Ben Junya
12,365 Points

Thanks Stone!

Treehouse uses the latest version of Python. Would I be able to use the skills from these courses in my own development since I'm working with GAE and Python 2.7?

I've already had some difficulties using my own terminal running 2.7, as many of the commands (namely "input" vs "raw_input") are giving me some compiling and syntax errors.

Please advise. Thanks!

Ben

Kenneth Love
STAFF
Kenneth Love
Treehouse Guest Teacher
Kenneth Love
Kenneth Love
Treehouse Guest Teacher

Things to keep in mind:

  • Write your Python 2 code like it's Python 3
  • To do this, be sure to use the __future__ module as much as possible, especially the print_function, and division features
  • Always define your classes as extending from object. class Foo(object): (Python 2 needs this to avoid Python 1-style classes (ugh) and Python 3 doesn't care)
  • If you have to do things differently based on version, use the six library instead of something like 2to3