Python 3.13 Changes May 2026

dp = DataProcessor() New: 'DataProcessor' object has no attribute 'process'. Did you mean: 'process_data'? try: dp.process() except AttributeError as e: print(e) 2. The copy Module Gets replace() Method A new method for creating modified copies of objects without mutation.

# Python 3.13 introduces __main__.py improvements if name == " main ": main() You can now use (in main .py): def main(): print("Running as main module") Python 3.13 automatically detects and runs main() in main .py No need for the if name guard in entry point modules 8. Security Enhancements import hashlib import ssl SHA-3 is now fully integrated and optimized def hash_demo(): data = b"Sensitive information"

# Async context manager performance async_setup = """ import asyncio class AsyncCM: async def (self): return self async def aexit (self, *args): pass """ python 3.13 changes

# Dictionary creation and access dict_setup = """ d = {} for i in range(1000): d[i] = i * 2 """

print("\n✅ Code ready for Python 3.13") Performance Comparison Example import timeit import sys def performance_showcase(): """Compare 3.12 vs 3.13 performance""" dp = DataProcessor() New: 'DataProcessor' object has no

# Better import error suggestions try: from collections import defaultdictt # Typo! except ImportError as e: print(e) # "cannot import name 'defaultdictt' from 'collections'. Did you mean: 'defaultdict'?" class DataProcessor: def process_data(self): pass

start = time.perf_counter() await main_new_way() new_time = time.perf_counter() - start The copy Module Gets replace() Method A new

if sys.version_info < (3, 13): warnings.warn("Not running on Python 3.13", RuntimeWarning) return