code I ripped off from someone on stack overflow

flatten.py

# https://stackoverflow.com/a/19647596/5114
def flatten_dict(dd, separator='_', prefix=''):
    return { prefix + separator + k if prefix else k : v
            for kk, vv in dd.items()
            for k, v in flatten_dict(vv, separator, kk).items()
            } if isinstance(dd, dict) else { prefix : dd }