检查每个项目 existing 列表位于 kafka_topics.keys() . 例子：

---
- hosts: localhost
  gather_facts: no
  connection: local
  vars:
    kafka_topics:
      topic1:
        partitions: 1
        replication_factor: 1
      topic2:
        partitions: 1
        replication_factor: 1
    existing:
      - topic1
      - topic2
      - topic3
      - topic4
  tasks:
    - debug:
        msg: "{{ item }} is not in 'kafka_topics'"
      with_items: "{{ existing }}"
      when: item not in kafka_topics.keys()

让您：

TASK [debug]*******************************************************************
skipping: [localhost] => (item=None)
skipping: [localhost] => (item=None)
ok: [localhost] => (item=None) => {
    "msg": "topic3 is not in 'kafka_topics'"
}
ok: [localhost] => (item=None) => {
    "msg": "topic4 is not in 'kafka_topics'"
}

替换 debug 用你想要的“行动”。
或者您可以使用 difference 过滤上述数据结构。