This article seeks to discuss lessons that may be learned from Python 2 and point out the change of features that are important to developers between Python 2 and Python 3. It incorporates areas and features including syntax change, the libraries, performance change, and how the changes may affect the development process. Knowing these distinctions will help developers make rational decisions on whether to port to Python 3 or start with Python 3.

Python has been developed as a language for computer science and still, Python 3 is more improved than Python 2. Even though the community has officially deprecated Python 2 from January 2020, there are still quite several systems which are running on Python 2.  It is important to understand the differences to facilitate developers who are willing to either extend from or create new Python 2-based systems.

1. Syntax and Compatibility

Syntax is one of the first things that have been changed when moving from Python 2 to Python 3. The New Syntax that Python 3 adopted includes the following which are not compatible with the previous Python 2.

• Print Function: Unlike Python 2, which was in the form of a print statement, that did not demand the use of parentheses, Python 3 is in the form of a function demanding the use of parentheses. For example, write a message saying Hello, World. Coerce to print ‘Hello, World’ in Python 2 is changed to print(“Hello, World!”) in Python 3.
• Unicode Handling: Newland explains that Python 3 has improved support for internationalization by making strings Unicode by default, as opposed to Python 2’s ASCII strings. Programmers who use Python on operations involving different text data will find the enhanced support for Unicode in Python 3 useful.

2. Integer Division

In Python 2, when dividing two integers the division operation gives integer division which removes the decimal part. For example, if we had 5 and divided by 2 it will return 2 in Python 2. However, Python 3 provides a float as the most precise answer to the above operation (for example, 5/2 is equal to 2.5). This change alone clears up many bugs that are dealt with in calculations.

3. Library Support

Today, a vast majority of third-party libraries and packages switched to supporting only Python 3. Some of the developers who are now coding with Python 2 are likely to discover that they cannot download new packages or updated versions of existing packages that are integrated more for Python 3 compatibility. If you are beginning a new program set or porting over an older set, Python 3 features a better and more latest environment.

4. Iterators and Generators

In Python 3 there have been improvements in how iterators and generators and thus iteration through a sequence is more memory friendly. The functions like range() return iterable object in Python 3 and not list which can be beneficial when you are working with systems that contain massive amounts of data. In Python 2 the range() function returns a list which is why it takes a lot of memory.

5. Error Handling

The syntax of exception handling also differs in Python 3 from that compared to Python 2. In Python 2, exceptions are caught using the syntax except for Exception, e: whereas Python 3 utilizes the more specific except Exception e: This change improves exception handling and aligns more with current-day coding standards.

6. Performance Improvements

Python 3 introduces several enhancements for the programming language mainly in efficiency and speed and improved architecture over its preceding version Python 2. Unlike Python 2, Python 3’s interpreter is designed for modern hardware, possibilities of multi-core processors are better implemented here. Therefore, Python 3 is more effective, especially in functions such as concurrency and memory management.

7. Community and Support

The Python Software Foundation formally no longer supports Python 2 starting from January this year as it no longer receives updates and security patches. Newer projects should be started in Python 3 because for bugs there will be community support in the indefinite and for new features.

8. Development Paradigms

Python 3 aligns with the current language standards from the use of type hints that improve code comprehension and in other scenarios where static analysis is viable. This is rather beneficial with large projects that require rigorous enforcement of code quality standards. Unfortunately, Python 2 does not have this feature which makes it even more cumbersome to use it in larger applications.

9. Migration Path

It is not always convenient to migrate from Python 2 to Python 3 because there are myriad differences between the two. The majority of these are available to aid the conversion from Python 2 to Python 3, which is the case with 2to3.  However, it may still be necessary to make manual changes depending on certain project requirements.

Conclusion

Therefore, this research concludes that the current version of Python, which is Python 3, holds striking advancement over Python 2 in aspects to do with syntax, performance, and support. Though Python 2 is still in use for some legacy applications for new applications, developers are encouraged to use Python 3 because Python 3 has more features than Python 2, the libraries for Python are more advanced, and a greater number of updates are being done on Python 3. It will be helpful if the developers realize these differences so that they know when and how to port over a current project or begin a new one in Python 3.