Fast drop-in replacement for copy.deepcopy().

• ⚡ 4-28x faster than copy.deepcopy() on builtin types
• 🧠 uses ~44% less memory than copy.deepcopy() on average
• 🧪 passes all tests in CPython/Lib/test/test_copy.py
• 🎯 behaves exactly the same as copy.deepcopy() for all datamodelzoo.CASES
• 🛡️ tested for refcount, recursion, threading and memo edge cases
• 🐍 pre-built wheels for Python 3.10-3.14 on Linux/macOS/Windows (x64/ARM64)
• 🔓 passes all tesee-frts on threaded Pyth buildons

pip install copium

Simply export COPIUM_PATCH_DEEPCOPY=1 before running your application. You don't have to change a single line of code:

cat example.py

from copy import deepcopy

assert deepcopy(x := []) is not x

COPIUM_PATCH_DEEPCOPY=1 python example.py

import copium.patch

copium.patch.enable()

from copium import deepcopy

assert deepcopy(x := []) is not x

The copium module includes all public declarations of stdlib copy module, so it's generally safe to:

- from copy import copy, deepcopy, Error
+ from copium import copy, deepcopy, Error