Python 2 released in 2000; legacy code, no longer supported after 2020.
Python 3 introduced in 2008; the future of Python, ongoing support.
Key differences in syntax, libraries, and error handling.
Python 2: Print statement print "Hello, world"
Python 3: Print function print("Hello, world")
Python 2: Dividing two integers results in an integer. 3 / 2 = 1
Python 3: Division results in a float. 3 / 2 = 1.5
Use // in Python 3 for integer division.
Python 2: Strings are ASCII by default.
Python 3: Strings are Unicode by default.
Better support for non-English languages and symbols in Python 3.
Python 2: xrange(), print, except Exception, e:
Python 3: range(), print(), except Exception as e:
More intuitive and consistent syntax in Python 3.
Python 2: Libraries may not be compatible with Python 3.
Python 3: A large number of Python 2 libraries have been updated or replaced.
Improved and more modern standard library in Python 3.
Python 2: Less strict about mixing types (e.g., bytes/str).
Python 3: Strict type checking, leading to fewer subtle bugs.
Python 3 offers significant improvements and future-proofing.
Migrating from Python 2 to 3 requires careful consideration but is encouraged for long-term projects.
Use tools like 2to3 for code translation and testing.
Python.org documentation
"Porting to Python 3" guide
Online tutorials and forums