Python versions

Posted on April 25, 2024 by Peter Andersson

Overview of major enhancements in each version

Python 3.6 (released December 2016)

Formatted string literals (f-strings):

name = "World"
print(f"Hello, {name}!")

Underscores in Numeric Literals:

billion = 1_000_000_000

Variable Annotations:

age: int = 25

Python 3.7 (released June 2018)

Data Classes:

from dataclasses import dataclass
@dataclass
class Point:
x: float
y: float

Asyncio Enhancements:

async def main():
await asyncio.sleep(1)
print('hello')

Built-in breakpoint():

breakpoint()  # Enters the debugger here.

Python 3.8 (released October 2019)

Walrus Operator (:=):
if (n := len(a)) > 10:
print(f"List is too long ({n} elements)")

Positional-Only Parameters:

def func(a, b, /, c, d):
return a + b + c + d

Python 3.9 (released October 2020)

Dictionary Merge (|) and Update (|=) Operators:

x = {"key1": "value1"}
y = {"key2": "value2"}
z = x | y

Type Hinting Generics in Standard Collections:

def greet_all(names: list[str]):
for name in names:
print("Hello", name)

Python 3.10 (released October 2021)

Structural Pattern Matching:

def http_error(status):
match status:
case 404:
return "Not found"
case 401 | 403:
return "Not allowed"

Parenthesized Context Managers:

with (open('file1.txt') as f1, open('file2.txt') as f2):
data = f1.read() + f2.read()

Python 3.11 (released October 2022)

Faster CPython: Performance improvements.
Exception Groups and except*:

try:
raise ExceptionGroup("Errors", [ValueError("wrong value"), TypeError("wrong type")])
except* ValueError as e:
print("Handled ValueError:", e)

Python 3.12 (released in October 2023)

Function Overloading with PEP 690:

class Calculator:
@overload
def add(self, a: int, b: int) -> int: ...
@overload
def add(self, a: float, b: float) -> float: ...
def add(self, a, b):
return a + b

Development