Many, one fun one that comes to mind is last year I made a Python debugger to output error traces exactly how I want to see them. It can display local variables

Many, one fun one that comes to mind is last year I made a Python debugger to output error traces exactly how I want to see them. It can display local variables, print the surrounding lines of code and parent function & class name at each trace for context. I also made a custom debugging print function to print variable names as well as their value with only having to write "print(var)". It also will print the parent function and class names for context. I use this tool more than the debugger day to day now. I know there are existing alternatives for one or both of these but there's nothing easier than tweaking a tool you wrote yourself. Plus I learned a lot about Python in the process!