# How to pass actual python type (such as None) in yaml using a variable **URL:** \ **Category:** Ansible Project\ **Created:** [October 10, 2013, 9:57pm UTC](https://forum.ansible.com/t/how-to-pass-actual-python-type-such-as-none-in-yaml-using-a-variable/13660 "2013-10-10T21:57:25Z")\ **Posts on this page:** 6\ **Page:** 1
**Author:** ![Andy1](https://avatars.discourse-cdn.com/v4/letter/a/a8b319/32.png) [@Andy1](https://forum.ansible.com/u/Andy1)\ **Post date:** [October 10, 2013, 9:57pm UTC](https://forum.ansible.com/t/how-to-pass-actual-python-type-such-as-none-in-yaml-using-a-variable/13660/1 "2013-10-10T21:57:25Z")
Hi, My problem is described here (MWE): [http://pastebin.com/27k4HHaU](http://pastebin.com/27k4HHaU) Some modules allow you to pass yaml’s null as a param which ends up as a python’s None. For instance the mysql\_user module here: [https://github.com/ansible/ansible/blob/devel/library/database/mysql\_user#L164](https://github.com/ansible/ansible/blob/devel/library/database/mysql_user#L164) won’t change the password when null is passed: - name: setup.mysql mysql\_user: password: null will only change privileges but not passwords (which the user may change). However if I pass a variable - name: setup mysql mysql\_user: password: “{{ pw }}” I can’t get it to work properly (as shown in the pastebin). This is with the latest devel. Is there a way to get that behavior? Right now I have to create two lists (one which enforces passwords, one which does not). Cheers ---
**Author:** ![Brian\_Coca1](https://avatars.discourse-cdn.com/v4/letter/b/278dde/32.png) [@Brian\_Coca1](https://forum.ansible.com/u/Brian_Coca1)\ **Post date:** [October 10, 2013, 9:58pm UTC](https://forum.ansible.com/t/how-to-pass-actual-python-type-such-as-none-in-yaml-using-a-variable/13660/2 "2013-10-10T21:58:57Z")
password: !!null there are other ways, but this is probably easiest to remember. ---
**Author:** ![Andy1](https://avatars.discourse-cdn.com/v4/letter/a/a8b319/32.png) [@Andy1](https://forum.ansible.com/u/Andy1)\ **Post date:** [October 10, 2013, 10:13pm UTC](https://forum.ansible.com/t/how-to-pass-actual-python-type-such-as-none-in-yaml-using-a-variable/13660/3 "2013-10-10T22:13:57Z")
I’m confused. I can pass already null. Can you give me a working example how to do that with variables? It seems ansible is not passing the type’s properly to the module, even though it does show python’s ‘None’ when using with\_items and passing and array of maps. ---
**Author:** ![Michael\_DeHaan2](https://avatars.discourse-cdn.com/v4/letter/m/da6949/32.png) [@Michael\_DeHaan2](https://forum.ansible.com/u/Michael_DeHaan2)\ **Post date:** [October 10, 2013, 11:59pm UTC](https://forum.ansible.com/t/how-to-pass-actual-python-type-such-as-none-in-yaml-using-a-variable/13660/4 "2013-10-10T23:59:03Z")
Variables typically stringify when invoked Something I’m looking to tweak soon. Consider using “” to mean no value set and you’ll be ok. ---
**Author:** ![Andy1](https://avatars.discourse-cdn.com/v4/letter/a/a8b319/32.png) [@Andy1](https://forum.ansible.com/u/Andy1)\ **Post date:** [October 11, 2013, 4:12pm UTC](https://forum.ansible.com/t/how-to-pass-actual-python-type-such-as-none-in-yaml-using-a-variable/13660/5 "2013-10-11T16:12:56Z")
So does that mean that the “null” I pass should actually not evaluate to python’s “None”? Does that mean my playbook is going to break in the future? What is the spec? I think I’ve kind of been misunderstood with this post. The actual issue is shown in detail in the pastebin link (if you have a second, run it’ll become clear). So I take it the “null” is just and accidental (undocumented) feature that I’m using? If not, and this is a feature, then I’d consider this behavior a bug since the variable substitution seems to loose the type at some point and it doesn’t look like there is a way to get it to behave properly. FWIW, I just split up the mysql\_user in two calls (one which passes “null” directly and one which passes “{{ item.pw }}”). Cheers ---
**Author:** ![Michael\_DeHaan2](https://avatars.discourse-cdn.com/v4/letter/m/da6949/32.png) [@Michael\_DeHaan2](https://forum.ansible.com/u/Michael_DeHaan2)\ **Post date:** [October 11, 2013, 8:47pm UTC](https://forum.ansible.com/t/how-to-pass-actual-python-type-such-as-none-in-yaml-using-a-variable/13660/6 "2013-10-11T20:47:33Z")
IMHO, you shouldn’t be thinking about a “null” in Ansible. It’s a memory management concept, and Ansible is not a programming language.