Python 2 vs 3

Python 3 value of variables never changes whereas in Python 2 value of the global variable will be changed while using it inside for-loop. Created by the BeOpen Python Labs team, the purpose of the introduction of Python 2 was to make programming simple and easy to learn for the common mass.

For the longest time, most developers chose Python 2 over Python 3 because most of the Python ecosystem was written in the former, even though the latter was a big improvement. It took quite a few years for most of these third-party libraries to be upgraded to Python 3. But now, you’ll find a larger selection of libraries supporting Python 3 than the older version. And, as of the beginning of 2020, Python 2 is no longer being developed.

The Key Differences Between Python 2 and Python 3

Character encoding is how a programming language stores characters in bytes. Python 2’s default character encoding, ASCII, only allowed for the use of letters, digits, and punctuation marks.

Python 2.x and Python 3.x are two of the most used python versions in real-world application development.They both come with a lot of features and library support. This article explores the major differences between python 2.x and 3.x, starting with a brief introduction to each version. Unless there is a clear reason for choosing one version of Python over the other, such as needing to work on existing code written in Python 2, then it is not worth worrying too much about the decision. Most of the syntax is the same in each version of the language. There are many other examples of slight differences in syntax between Python 2 and Python 3.

Skillshare: Python 3: A Beginners Guide to Python Programming

Python 3.0 also known as “Python 3000” or “Py3K”, which was released on December 3, 2008, was the first-ever intentionally backward-incompatible Python release. It introduced many changes in the fundamental design which posed an issue in python 2.5 and python 2.6 at that time.

Once you are able to fully run under Python 3 you will want to make sure your code always works under both Python 2 & 3. Probably the best tool for running your tests under multiple Python interpreters is tox. You can then integrate tox with your continuous integration system so that you never accidentally break Python 2 or 3 support. Once you have fully translated your code to be compatible with Python 3, you will want to make sure your code doesn’t regress and stop working under Python 3. This is especially true if you have a dependency which is blocking you from actually running under Python 3 at the moment.