Merge 2 lists in robot framework - list

Question

Below are my 2 lists:
a: ['a0', 'a3']
b: ['b0', 'b1', 'b0', 'b1']
I need to merge the above 2 list as below:
final: ['a0b0', 'a0b1', 'a3b0', 'a3b1']
Need to write a for loop which will check for "0" in list b and then start with the next element in list a.
Thanks,

Answer 1

If I understand the rules, you need to combine two lists such as:
items from both lists will be combined, items from the first list will come first (e.g. "a0" and "b1" will become "a0b1")
there could be repeating items in both lists but you don't want these repetitions to be present in the final list
I think Python is your best friend here, I'd propose this piece of code as a custom library:
Libraries/ListUtils.py
def combine_lists(list1, list2):
set1 = set(list1)
set2 = set(list2)
final_list = []
for i1 in set1:
for i2 in set2:
final_list.append("{}{}".format(i1, i2))
return final_list
and an example test case:
*** Settings ***
Library ../Libraries/ListUtils.py
Library Collections
*** Test Cases ***
Combine Lists
${list1}= Create List a0 a3
${list2}= Create List b0 b1 b0 b1
${final_list}= Combine Lists ${list1} ${list2}
Log To Console ${final_list}
This will log into console:
['a3b1', 'a3b0', 'a0b1', 'a0b0']
which is the output you specified in your question. It's not ordered in any way, you might want to add this to it.
Also note that there's Combine Lists keyword in Collections library (but this one does something else than you want). As a result of that, my example will produce one warning:
[ WARN ] Keyword 'Combine Lists' found both from a custom test library 'ListUtils' and a standard library 'Collections'. The custom keyword is used. To select explicitly, and to get rid of this warning, use either 'ListUtils.Combine Lists' or 'Collections.Combine Lists'.
So you might want to pay more attention to naming conventions, or call keywords by their full name like e.g. Collections.Combine Lists.