# Python 3.12: NameError: name 'prnt' is not defined # Python 3.13: NameError: name 'prnt' is not defined. Did you mean 'print'? | Operation | 3.12 (sec) | 3.13 (sec) | Improvement | |------------------------|------------|------------|--------------| | Recursive fibonacci(35)| 3.2 | 2.3 | 28% | | JSON load/dump (1MB) | 0.14 | 0.10 | 29% | | Regex search (email) | 1.8 µs | 1.3 µs | 28% |

pip install pyupgrade pyupgrade --py313-plus your_project/ Step 1: Test with -X warn_default_encoding python3.13 -X warn_default_encoding your_script.py Fixes silent encoding="utf-8" assumptions in open() . Step 2: Update type hints pip install ruff ruff check --select UP . Step 3: Handle no-GIL compatibility If you use C extensions:

# Linux (deadsnakes PPA) sudo add-apt-repository ppa:deadsnakes/ppa sudo apt install python3.13 python3.13-full brew install python@3.13 Windows (official installer) Download from python.org/downloads/release/python-313/

A: For pure-Python CPU-bound workloads – yes. For numpy/pandas – test carefully. For Django/Flask – not yet (GIL still assumed by many async DB drivers).