Flatten dictionary

flatten.py

def flatten(data):
    """Flatten a nested dict.

    Args:
        data (dict): The dictionary to flatten

    Returns:
        dict: Flattened dictionary
    """
    out = {}
    for key, val in data.items():
        if isinstance(val, dict):
            val = [val]
        if isinstance(val, list):
            for subdict in val:
                out.update(flatten(subdict))
        else:
            out[key] = val
    return out