Recursively lowercase all elements - accepts list, str, tuple, dict, set

python_lowercase_recursive.py

def lowercase_everything(obj):
    """ Recursively lowercase all elements - accepts list, str, tuple, dict, set """
    if isinstance(obj, dict):
        return {k.lower(): _lowercase(v) for k, v in obj.items()}
    elif (t := type(obj)) in (list, set, tuple):
        return t(_lowercase(o) for o in obj)
    elif isinstance(obj, str):
        return obj.lower()
    return obj

There's a walrus := operator in there, so you'll need to be using python3.8.