eval_sexpr.py

def eval_sexpr(sexpr):
    fn = sexpr[0]
    args = sexpr[1:]
    args = tuple(eval_sexpr(e) if isinstance(e, tuple) else e for e in args)
    return fn(*args)


import operator as op
eval_sexpr((op.add, (op.mul, 3, 4), (op.mul, 2, 5)))