class NestedDataStructure:
    def __init__(self, data=None):
        self.data = data if data is not None else []

    def flatten(self, data=None):
        data = data if data is not None else self.data
        if isinstance(data, dict):
            return self.flatten(list(data.values()))
        elif isinstance(data, (list, tuple)):
            return [flattened for item in data for flattened in self.flatten(item)]
        else:
            return [data]
/Users/nielsrogge/Documents/python_projecten/datasets/src/datasets/utils/py_utils.py