Python 2 vs Python 3: Key Differences and When to Use Each

Python 3 is the modern version of Python with improved syntax like print() as a function and better Unicode support, while Python 2 uses print as a statement and has different integer division behavior. Python 3 is recommended for new projects because Python 2 is no longer maintained.

Quick Comparison

Here is a quick side-by-side comparison of Python 2 and Python 3 on key features.

Feature	Python 2	Python 3
Print statement	print 'Hello'	print('Hello')
Integer division	Truncates result: 3 / 2 == 1	True division: 3 / 2 == 1.5
Unicode support	Separate str and unicode types	All strings are Unicode by default
Library support	Many older libraries only support Python 2	Most modern libraries support Python 3 only
End of life	Officially unsupported since 2020	Actively maintained and improved

Key Differences

Python 3 introduced several important changes to make the language cleaner and more consistent. One major change is that print became a function, so you must use parentheses like print('Hello'). In contrast, Python 2 uses print as a statement without parentheses.

Another key difference is how division works. In Python 2, dividing two integers truncates the decimal part (e.g., 3 / 2 == 1), which can cause bugs. Python 3 fixes this by making division always return a float (e.g., 3 / 2 == 1.5), matching most people's expectations.

Unicode handling is also improved in Python 3. All strings are Unicode by default, making it easier to work with international text. In Python 2, you had to use a separate unicode type explicitly, which was confusing and error-prone.

Code Comparison

Here is a simple example showing how to print a message and divide numbers in Python 2.

python

print 'Hello from Python 2'
print 3 / 2

Output

Hello from Python 2
1

Python 3 Equivalent

The same example in Python 3 uses the print function and true division.

python

print('Hello from Python 3')
print(3 / 2)

Output

Hello from Python 3
1.5

When to Use Which

Choose Python 3 for all new projects because it is actively maintained, supports modern features, and has better Unicode and division behavior. Most libraries now support only Python 3.

Use Python 2 only if you must maintain or run legacy code that has not been updated, but plan to upgrade soon since Python 2 is no longer supported.

Key Takeaways

Python 3 uses print() as a function; Python 2 uses print as a statement.

Division in Python 3 returns float results; Python 2 truncates integer division.

Python 3 has better Unicode support with all strings as Unicode by default.

Python 2 reached end-of-life in 2020; Python 3 is the future of Python.

Always prefer Python 3 for new projects and library compatibility.