Deap function composition as alternative to eval lamba expression in lambdify.

gistfile1.py

def _lookup(pos):
    def composition(*args):
        return args[pos]
    return composition


def _apply(func, *funcs):
    def composition(*args):
        return func(*(f(*args) for f in funcs))
    return composition


def compose(expr, pset):
    stack = []
    for node in expr:
        stack.append((node, []))
        while len(stack[-1][1]) == stack[-1][0].arity:
            prim, funcs = stack.pop()
            if isinstance(prim, gp.Terminal):
                func = _lookup(pset.arguments.index(prim.value))
            else:
                func = _apply(expr.pset.context[prim.name], *funcs)

            if len(stack) == 0:
                break
            stack[-1][1].append(func)

    return func


def composeADF(expr):
    adfdict = {}
    func = None
    for subexpr in reversed(expr):
        subexpr.pset.context.update(adfdict)
        func = compose(subexpr, subexpr.pset)
        adfdict.update({subexpr.pset.__name__: func})
    return func