a = [1,2,3,[1,2]]

 b = a

 b is a # True

 c = list[a] # shallow copy

 c is a # False

 c[3][0] = 100

 a # [1,2,3,[100,2]]

 import copy

 d = copy.deepcopy(a) # deep copy, recusion

 d[3][0] = 99

 a # [1,2,3,[100,2]]

 line = "Good, 100, 490.10"

 foo = line.split(',')

 result = [str(foo[0]), int(foo[1]), float(foo[2])]

 print result

 line = "Good, 100, 490.10"

 foo = line.split(',')

 t = [str, int, float]

 result = [ty(val) for ty,val in zip(t, foo)]

 print result

 f = open("data.txt")

 lines = (t.strip() for t in f)

 comments = (t for t in lines if t[0] == '#')

 for c in comments:

     print(c)