Evolution of Python Functions: From 2.7 to 3.12 (with Code Examples)

Python has come a long way since 2.7.
Back then:

• print was still a statement
• type hints didn’t exist
• % formatting was the default

Today, we write functions very differently.

# Python 2.7
def greet(name):
    print "Hello, %s" % name

# Python 3.10+
def greet(name: str) -> str:
    return f"Hello, {name}"

And with Python 3.12, we even get more concise typing with list[str], | for unions, and better error messages.

In my full article, I walk through:

• Type hints (from typing.List[str] → list[str])
• F-strings replacing % and .format()
• Structural Pattern Matching (Python 3.10)
• Why print had to change from statement → function

Read the full deep dive on Medium: Evolution of Functions in Python: From Python 2.7 to Today