Using any custom character for commenting in Ansible comment filter ({{ … | comment }})

I needed to have comment in a PHP ini file where the prefix for commenting is `;`, This is something I didn’t find in the documentation for the comment filter, so I looked in the code for the comment (in my case: `/usr/lib/python2.7/site-packages/ansible/plugins/filter/core.py`)

def combine(*terms, **kwargs):
    recursive = kwargs.get('recursive', False)
    if len(kwargs) > 1 or (len(kwargs) == 1 and 'recursive' not in kwargs):
        raise errors.AnsibleFilterError("'recursive' is the only valid keyword argument")

    for t in terms:
        if not isinstance(t, dict):
            raise errors.AnsibleFilterError("|combine expects dictionaries, got " + repr(t))

    if recursive:
        return reduce(merge_hash, terms)
    else:
        return dict(itertools.chain(*map(iteritems, terms)))

def comment(text, style='plain', **kw):
    # Predefined comment types
    comment_styles = {
        'plain': {
            'decoration': '# '
        },
        'erlang': {
            'decoration': '% '
        },
        'c': {
            'decoration': '// '
        },
        'cblock': {
            'beginning': '/*',
            'decoration': ' * ',
            'end': ' */'
        },
        'xml': {
            'beginning': '<!--',
            'decoration': ' - ',
            'end': '-->;'
        }
    }

    # Pointer to the right comment type
    style_params = comment_styles[style]

    if 'decoration' in kw:
        prepostfix = kw['decoration']
    else:
        prepostfix = style_params['decoration']

And found the `decoration` keyword (which does not mention in the documentations), so I tried using it like this,
{{ ansible_managed | comment(decoration='; ') }}
And it works 🙂

;
; This file is managed by Ansible.
;
; template: /vagrant/provisioning/roles/backend/templates/php/xdebug.ini.j2
; date: 2017-05-24 12:32:27
; user: rabin
; host: localhost
;