swap two elements in a list python

1    i = ['title', 'email', 'password2', 'password1', 'first_name', 
2         'last_name', 'next', 'newsletter']
3    a, b = i.index('password2'), i.index('password1')
4    i[b], i[a] = i[a], i[b]

1lst = ["a","b","c","d","e","f","g","h","i","j"]
2n = len(lst)
3for i in range(0,n-1,2):
4    lst[i],lst[i+1] = lst[i+1],lst[i]
5print(lst)
6print(n)

1list[pos1], list[pos2] = list[pos2], list[pos1]