jinja2动态导航到json对象[复制]

时间：2022-11-23 08:59:02

This question already has an answer here:

这个问题在这里已有答案:

My question looks trivial but I already spend some hours on it.

我的问题看起来微不足道,但我已经花了几个小时。

How to dynamically navigate into a json variable, with jinja2. ex: I get

如何使用jinja2动态导航到json变量。例如:我明白了

ansible_lvm.vgs:
    "vgs": {
                "vgdata": {
                    "free_g": "16",
                    "size_g": "0"
                },
                "vgswap": {
                    "free_g": "0",
                    "size_g": "00"
            }
        }

In a jinja2 structure I would like to get "free_g" attribut for "vgdata": None of the code hereafter works:

在jinja2结构中,我想得到“free_g”attribut for“vgdata”:以后的代码都不起作用:

   {% set my_vg_name = 'vg_data' %}
   {% set my_vg_size = ansible_lvm.vgs.(my_vg_name).free_g %}
   {% set my_vg_size = ansible_lvm.vgs.{{my_vg_name}}.free_g %}
   {% set my_vg_size = ansible_lvm.vgs|selectattr(my_vg_name, 'free_g') %}

Thanks for your help,

谢谢你的帮助,

1 个解决方案

#1

0  

So, I hope that code snippet at the top is just an example, and not really what you are using, since it's malformed JSON. And I hope you are not actually asking the vgs object for vg_data when the key is vgdata, because that will never end well.

所以,我希望顶部的代码片段只是一个例子,而不是你正在使用的代码片段,因为它是错误的JSON。并且我希望当密钥是vgdata时,你实际上并没有要求vg_data的vgs对象,因为它永远不会结束。

That aside:

You access dict objects in python using vgs[my_vg_name] syntax, or if you aren't sure that vgs contains that key, vgs.get(my_vg_name, {}) to provide an empty dict as the default if vgs does not contain a key whose value is in the my_vg_name variable.

您可以使用vgs [my_vg_name]语法在python中访问dict对象,或者如果您不确定vgs是否包含该密钥,则vgs.get(my_vg_name,{})如果vgs不包含密钥则提供空dict作为默认值其值在my_vg_name变量中。

Perhaps it's just a bad question, but if you always want vgdata.free_g then why the dynamic access at all?

也许这只是一个糟糕的问题,但如果你总是想要vgdata.free_g那么为什么动态访问呢?

#1

0  

So, I hope that code snippet at the top is just an example, and not really what you are using, since it's malformed JSON. And I hope you are not actually asking the vgs object for vg_data when the key is vgdata, because that will never end well.

所以,我希望顶部的代码片段只是一个例子,而不是你正在使用的代码片段,因为它是错误的JSON。并且我希望当密钥是vgdata时,你实际上并没有要求vg_data的vgs对象,因为它永远不会结束。

That aside:

You access dict objects in python using vgs[my_vg_name] syntax, or if you aren't sure that vgs contains that key, vgs.get(my_vg_name, {}) to provide an empty dict as the default if vgs does not contain a key whose value is in the my_vg_name variable.

您可以使用vgs [my_vg_name]语法在python中访问dict对象,或者如果您不确定vgs是否包含该密钥,则vgs.get(my_vg_name,{})如果vgs不包含密钥则提供空dict作为默认值其值在my_vg_name变量中。

Perhaps it's just a bad question, but if you always want vgdata.free_g then why the dynamic access at all?

也许这只是一个糟糕的问题,但如果你总是想要vgdata.free_g那么为什么动态访问呢?

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