# Combining 2 lists of strings with a separator **URL:** \ **Category:** Ansible Project\ **Created:** [September 27, 2017, 2:30pm UTC](https://forum.ansible.com/t/combining-2-lists-of-strings-with-a-separator/25612 "2017-09-27T14:30:54Z")\ **Posts on this page:** 5\ **Page:** 1
**Author:** ![actionmystique](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/actionmystique/32/1678_2.png) [@actionmystique](https://forum.ansible.com/u/actionmystique)\ **Post date:** [September 27, 2017, 2:30pm UTC](https://forum.ansible.com/t/combining-2-lists-of-strings-with-a-separator/25612/1 "2017-09-27T14:30:54Z")
hello guys, I need to build filenames based on 3 parts: basename, version and trailing ‘.x86\_64.rpm’. Let’s focus on the first 2 parts: The first one is: “installed\_mtx\_packages\_name”: [ “mtx-device”, “mtx-grpc-agent”, “mtx-infra”, … ] The second one is: “installed\_mtx\_packages\_version”: [ “1.0.0-r1705191346”, “1.0.1-r1705191346”, “1.0.0-r1705170158”, … ] the goal is to obtain this: “installed\_mtx\_packages\_partialname”: [ “mtx-device-1.0.0-r1705191346”, “mtx-grpc-agent-1.0.0-r1705191346”, “mtx-infra-1.0.0-r1705170158”, … ] I’ve tried several strategies, including: - name: Building partial name of installed MTX packages set\_fact: installed\_mtx\_packages\_partialname: “{{ installed\_mtx\_packages\_name | map(‘regex\_replace’, ‘(.\*)’, ‘\1-item’) | list }}” with\_items: installed\_mtx\_packages\_version But of course the item is considered as a string here instead of a variable. If I move the ’ just before item, I get the error: "template error while templating string: expected token ‘,’, got ‘string’ " Any suggestion? ---
**Author:** ![azaghal](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/azaghal/32/4743_2.png) [@azaghal](https://forum.ansible.com/u/azaghal)\ **Post date:** [September 27, 2017, 3:56pm UTC](https://forum.ansible.com/t/combining-2-lists-of-strings-with-a-separator/25612/2 "2017-09-27T15:56:34Z")
> hello guys, > I need to build filenames based on 3 parts: basename, version and > trailing '.x86\_64.rpm'. > Let's focus on the first 2 parts: > The first one is: >         "installed\_mtx\_packages\_name": [ >             "mtx-device", >             "mtx-grpc-agent", >             "mtx-infra", > ... >         ] > > The second one is: >         "installed\_mtx\_packages\_version": [ >             "1.0.0-r1705191346", >             "1.0.1-r1705191346", >             "1.0.0-r1705170158", > ... >         ] > > the goal is to obtain this: >          "installed\_mtx\_packages\_partialname": [ >             "mtx-device-1.0.0-r1705191346", >             "mtx-grpc-agent-1.0.0-r1705191346", Should this line be "mtx-grpc-agent-1.0.1-r1705191346" by any chance? Just checking if the example might be a typo 🙂 >             "mtx-infra-1.0.0-r1705170158", > ... >         ] This is not an answer for your question, but maybe a nudge to rethink it if possible - do you absolutely have to form these as two separate lists? Where do the installed\_mtx\_packages\_name and installed\_mtx\_packages\_version variables come from? Command, some external file? Otherwise, you may want to look at this (if I understood your requirements well): [https://docs.ansible.com/ansible/latest/playbooks\_loops.html#looping-over-parallel-sets-of-data](https://docs.ansible.com/ansible/latest/playbooks_loops.html#looping-over-parallel-sets-of-data) > I've tried several strategies, including: > - name: Building partial name of installed MTX packages >   set\_fact: >         installed\_mtx\_packages\_partialname: > "{{ installed\_mtx\_packages\_name | map('regex\_replace', '(.\*)', > '\\1-item') | list }}" with\_items: installed\_mtx\_packages\_version > > But of course the item is considered as a string here instead of a > variable. > > If I move the ' just before item, I get the error: > "template error while templating string: expected token ',', got > 'string' " Not 100% sure what you mean by "just before item", but I'm assuming you'd want (e.g. note the "'\\1-' + item" part - you can concatenate strings this way): "{{ installed\_mtx\_packages\_name | map('regex\_replace', '(.\*)', '\\1-' + item) | list }}" Additionally, you should switch to using (I think without moustaches this would iterate over an item literal "installed\_mtx\_packages\_version" otherwise): with\_items: "{{ installed\_mtx\_packages\_version }}" To top it off - I'm pretty sure this particular loop would not produce the list you desire. Best regards ---
**Author:** ![actionmystique](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/actionmystique/32/1678_2.png) [@actionmystique](https://forum.ansible.com/u/actionmystique)\ **Post date:** [September 28, 2017, 10:14am UTC](https://forum.ansible.com/t/combining-2-lists-of-strings-with-a-separator/25612/3 "2017-09-28T10:14:58Z")
@branko - you’re right about the typo. - your “‘\1-’ + item” solution works beautifully 🙂 The solution hence is: - name: Building partial name of installed MTX packages set\_fact: installed\_mtx\_packages\_partial\_name: “{{ installed\_mtx\_packages\_name | map(‘regex\_replace’, ‘(.\*)’, ‘\1-’ + item) | list }}” with\_items: “{{ installed\_mtx\_packages\_version }}” The result is: “installed\_mtx\_packages\_partial\_name”: [ “mtx-device-1.0.1-r1705191346”, “mtx-grpc-agent-1.0.1-r1705191346”, “mtx-infra-1.0.1-r1705191346”, … ] Thanks! ---
**Author:** ![actionmystique](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/actionmystique/32/1678_2.png) [@actionmystique](https://forum.ansible.com/u/actionmystique)\ **Post date:** [September 29, 2017, 1:00pm UTC](https://forum.ansible.com/t/combining-2-lists-of-strings-with-a-separator/25612/4 "2017-09-29T13:00:54Z")
@branko Sorry for the false positive, **actually your solution does not work** : it loops over all versions as expected, but it puts each item at the end of each name for each iteration, so the final list is (as shown in previous post): “installed\_mtx\_packages\_partial\_name”: [ “mtx-device-1.0.1-r1705191346”, “mtx-grpc-agent-1.0.1-r1705191346”, “mtx-infra-1.0.1-r1705191346”, … ] As you can see (and I missed it the first time), all the elements have the same version, instead of its own. ---
**Author:** ![actionmystique](https://sea1.discourse-cdn.com/ansible/user_avatar/forum.ansible.com/actionmystique/32/1678_2.png) [@actionmystique](https://forum.ansible.com/u/actionmystique)\ **Post date:** [September 29, 2017, 1:24pm UTC](https://forum.ansible.com/t/combining-2-lists-of-strings-with-a-separator/25612/5 "2017-09-29T13:24:55Z")
The true solution is tricky: - name: Building partial name of installed MTX packages set\_fact: installed\_mtx\_packages\_partial\_name\_item: “{{ item.0 }}-{{ item.1 }}” with\_together: - “{{ installed\_mtx\_packages\_name }}” - “{{ installed\_mtx\_packages\_version }}” register: installed\_mtx\_packages\_partial\_name\_result - name: Building partial list of name of installed MTX packages set\_fact: installed\_mtx\_packages\_partial\_name: “{{ installed\_mtx\_packages\_partial\_name\_result.results | map(attribute=‘ansible\_facts.installed\_mtx\_packages\_partial\_name\_item’) | list }}” leads to the true list: “installed\_mtx\_packages\_partial\_name”: [ “mtx-infra-1.0.0-r1705191346”, “mtx-device-1.0.0-r1705191346”, “mtx-grpc-agent-1.0.1-r1705191346”, … ] There might be a more elegant solution.