def flatten(l):
    if isinstance(l,list) or isinstance(l,tuple):
        return functools.reduce(operator.add, (flatten(x) for x in l), [])
    return [l]
Called if no request info is passed to the form.  Might lookup
dataset/ETHPy150Open Microsoft/ivy/src/ivy/ivy_utils.py/flatten--crossover with--dataset/ETHPy150Open mitsuhiko/fungiform/fungiform/forms.py/FormBase._lookup_request_info