iterate through an array python

1list = [1, 3, 6, 9, 12] 
2   
3for i in list: 
4    print(i) 

1foo = ['foo', 'bar']
2for i in foo:
3  print(i) #outputs 'foo' then 'bar'
4for i in range(len(foo)):
5  print(foo[i]) #outputs 'foo' then 'bar'
6i = 0
7while i < len(foo):
8  print(foo[i]) #outputs 'foo' then 'bar'

1colors = ["red", "green", "blue", "purple"]
2i = 0
3while i < len(colors):
4    print(colors[i])
5    i += 1
6

1for i in foo:
2  print(i) #outputs 'foo' then 'bar'