How do I concatenate two lists in Python?

Question

How do I concatenate two lists in Python?

Example:

listone = [1, 2, 3]
listtwo = [4, 5, 6]

Expected outcome:

>&g         


        

Answer 1

I assume you are wanting one of the two methods:

Keep Duplicate elements

It is very easy, just concatenate like string:

def concat_list(l1,l2):
    l3 = l1+l2
    return l3

Next if you want to eliminate duplicate elements

def concat_list(l1,l2):
   l3 = []
   for i in [l1,l2]:
     for j in i:   
       if j not in l3:   
         #Check if element exists in final list, if no then add element to list
         l3.append(j)
   return l3