how to create an array from a list in python

1def tips_unfold(fn, seed):
2  def fn_generator(val):
3    while True: 
4      val = fn(val[1])
5      if val == False: break
6      yield val[0]
7  return [i for i in fn_generator([None, seed])]
8
9f = lambda n: False if n > 50 else [-n, n + 10]
10print(tips_unfold(f, 10))
11