dictionary - Ansible - 如何比较两个具有相同键的字典

Question

我有两个字典:

source_list:
  myFlag1: true
  MyFlag2: false

第二个字典:

target_list:
  MyFlag1: false
  MyFlag2: false

key 总是相同的，但顺序并不严格。我怎样才能突出它们之间的区别？我可以使用 dict2items 将列表转换为

source_list:
  - key: MyFlag1
    value: true
  - key: MyFlag2
    value: false

但是我又很困惑，我怎么比较它们……当然，我可以循环遍历两个字典并一个一个地比较它，但它看起来并不是很有效。任何帮助将不胜感激!

Answer 1

问题:“如何比较具有相同键值的两个字典？”

A:给定简化数据进行测试

    s:
      flag1: true
      Flag3: true
      flag2: false
    t:
      flag3: true
      flag1: false
      flag2: false

• 比较变量以简要找出是否存在任何差异，例如

    - debug:
        msg: The dictionaries are identical
      when: s == t
    - debug:
        msg: The dictionaries are different
      when: s != t

给予

  msg: The dictionaries are different

• 接下来，比较键，例如声明变量

    s_keys: "{{ s.keys()|list }}"
    t_keys: "{{ t.keys()|list }}"
    diff_keys: "{{ s_keys|symmetric_difference(t_keys) }}"

并测试symmetric_difference

的长度

    - debug:
        msg: "The difference in the keys: {{ diff_keys }}"
      when:  diff_keys|length != 0

给予

  msg: 'The difference in the keys: [''Flag3'', ''flag3'']'

• 让我们假设字典具有相同的键来查找不同的值，例如

    s:
      flag1: true
      flag3: true
      flag2: false
    t:
      flag3: true
      flag1: false
      flag2: false

• 迭代键列表并逐项比较字典，例如

    - debug:
        msg: "{{ item }} is {{ (s[item] == t[item])|ternary('OK', 'KO') }}"
      loop: "{{ s.keys()|sort }}"
      when:  diff_keys|length == 0

给予

  msg: flag1 is KO
  msg: flag2 is OK
  msg: flag3 is OK

---

问题:“我怎样才能突出它们之间的区别？”

A:创建一个只包含不同值的字典，例如

    - set_fact:
        diff_vals: "{{ diff_vals|d({})|combine({item: s[item]}) }}"
      loop: "{{ s.keys()|sort }}"
      when:
        - diff_keys|length == 0
        - s[item] != t[item]
    - debug:
        var: diff_vals

给予

  diff_vals:
    flag1: true

---

<支持>

完整剧本的示例

- hosts: localhost
  gather_facts: false

  vars:
    s:
      flag1: true
      flag3: true
      flag2: false
    t:
      flag3: true
      flag1: false
      flag2: false
    
    s_keys: "{{ s.keys()|list }}"
    t_keys: "{{ t.keys()|list }}"
    diff_keys: "{{ s_keys|symmetric_difference(t_keys) }}"

  tasks:

    - debug:
        msg: The dictionaries are identical
      when: s == t
    - debug:
        msg: The dictionaries are different
      when: s != t

    - debug:
        msg: "The difference in the keys: {{ diff_keys }}"
      when:  diff_keys|length != 0

    - debug:
        msg: "{{ item }} is {{ (s[item] == t[item])|ternary('OK', 'KO') }}"
      loop: "{{ s.keys()|sort }}"
      when:  diff_keys|length == 0

    - set_fact:
        diff_vals: "{{ diff_vals|d({})|combine({item: s[item]}) }}"
      loop: "{{ s.keys()|sort }}"
      when:
        - diff_keys|length == 0
        - s[item] != t[item]
    - debug:
        var: diff_vals