python copy method alters type

[Zhenhai Zhang]

Really weired; Here is my code:

    a = ["a", 1, 3, 4]
    print "a:", a
   
    c = copy(a)
    c[0] = "c"
    c[1] = 2
    print "c:", c
    print "a:",a

output as follows:

a: ['a', 1, 3, 4]
c: ['c' '2' '3' '4']
a: ['a', 1, 3, 4]

Btw, I'm using python 2.5. I'm very curious why the copied list changed 
data type.

Thanks,

Zhenhai