Function worked 10 times. Failed on the 11th. The bug was in my function signature.

1. 1Write a Python function with immutable default arguments to avoid unexpected behavior
2. 2Use the None pattern to initialize mutable default arguments
3. 3Test your function with different inputs to catch potential bugs
4. 4Review your function signatures for mutable default arguments
5. 5Apply the fix by changing the default argument to an immutable type or using the None pattern

Backend developers and DevOps engineers can benefit from understanding this common Python pitfall to avoid similar issues in production

💡 Python's mutable default arguments can retain their value between function calls, leading to unexpected behavior

🚨 Python's mutable default arguments can bite you in production! 🚨 Learn how to fix them with a one-line change 💻