Question

I need to step some elements from a list (in this case n)
I has also another list ( o list)

n=['A','B','C','D','E']
o=['A','B','C','D','E','AS','sd','Z','R']
n.sort()

Now if I use this code:

for o in sorted(n): 

The code is run for 'A','B','C','D','E'.

I need to run the for code but just only 'AS','sd','Z','R' items.

Something like : run the code for items from o list without items from n list

Answer 1

This works only if o has no duplicates:

n = ['A','B','C','D','E']
o = ['A','B','C','D','E','AS','sd','Z','R']
a = sorted(set(o) - set(n))

# a == ['AS', 'R', 'Z', 'sd']

otherwise use this:

n = ['A','B','C','D','E']
o = ['A','B','C','D','E','AS','sd','Z','R', 'AS']
s = set(n)
a = sorted(elem for elem in o if elem not in s)

# a == ['AS', 'AS', 'R', 'Z', 'sd']