community.general/plugins/filter/counter.py

# -*- coding: utf-8 -*-
# Copyright (c) 2021, Remy Keil <remy.keil@gmail.com>
# GNU General Public License v3.0+ (see COPYING or https://www.gnu.org/licenses/gpl-3.0.txt)

from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

DOCUMENTATION = '''
  name: counter
  short_description: Counts hashable elements in a sequence
  version_added: 4.3.0
  author: Rémy Keil (@keilr)
  description:
    - Counts hashable elements in a sequence.
  options:
    _input:
      description: A sequence.
      type: list
      elements: any
      required: true
'''

EXAMPLES = '''
- name: Count occurences
  ansible.builtin.debug:
    msg: >-
      {{ [1, 'a', 2, 2, 'a', 'b', 'a'] | community.general.counter }}
    # Produces: {1: 1, 'a': 3, 2: 2, 'b': 1}
'''

RETURN = '''
  _value:
    description: A dictionary with the elements of the sequence as keys, and their number of occurance in the sequence as values.
    type: dictionary
'''

from ansible.errors import AnsibleFilterError
from ansible.module_utils.common._collections_compat import Sequence
from collections import Counter


def counter(sequence):
    ''' Count elements in a sequence. Returns dict with count result. '''
    if not isinstance(sequence, Sequence):
        raise AnsibleFilterError('Argument for community.general.counter must be a sequence (string or list). %s is %s' %
                                 (sequence, type(sequence)))

    try:
        result = dict(Counter(sequence))
    except TypeError as e:
        raise AnsibleFilterError(
            "community.general.counter needs a sequence with hashable elements (int, float or str) - %s" % (e)
        )
    return result


class FilterModule(object):
    ''' Ansible counter jinja2 filters '''

    def filters(self):
        filters = {
            'counter': counter,
        }

        return filters