Changes [cracked]: Python 3.13

# 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

async_test = """ async def test(): async with AsyncCM(): pass """ python 3.13 changes

# Check for removed features checks = [ ("crypt", "Module 'crypt' removed in 3.13"), ("2to3", "Tool removed in 3.13"), ] # Better import error suggestions try: from collections

# Async context manager performance async_setup = """ import asyncio class AsyncCM: async def (self): return self async def aexit (self, *args): pass """ Removal of Deprecated Features # Things that no

dict_time = timeit.timeit(dict_test, setup=dict_setup, number=10000) print(f"Dictionary operations: dict_time:.3fs")

# New hash algorithms with better security blake3_hash = hashlib.blake2b(data, digest_size=32).hexdigest() print(f"BLAKE2b: blake3_hash[:16]...") def ssl_improvements(): # Default minimum TLS version is now 1.3 context = ssl.create_default_context() print(f"Minimum TLS version: context.minimum_version") print(f"Maximum TLS version: context.maximum_version") 9. Removal of Deprecated Features # Things that no longer work in Python 3.13: 1. 'u' string prefix (was deprecated since Python 3.3) u"text" # SyntaxError in 3.13 2. crypt module removed (use hashlib or passlib instead) import crypt # ModuleNotFoundError 3. 2to3 tool removed (use pyupgrade or modernize) 4. Old-style datetime formatting from datetime import datetime dt = datetime.now() dt.strftime("%Y-%m-%d") # Still works But %z without colon is deprecated 5. asyncio.coroutine decorator removed (use async/await) @asyncio.coroutine # AttributeError def old_style(): pass 10. New Environment Variables # Enable experimental JIT compiler export PYTHON_JIT=1 Configure JIT threshold (when to compile hot code) export PYTHON_JIT_THRESHOLD=1000 Disable new error message suggestions (for CI) export PYTHON_COLORS=0 Configure asyncio debug level export PYTHONASYNCIODEBUG=2 Migration Checklist # Check your code for compatibility with Python 3.13 import sys import warnings