如何将 YAML 文件解析/读取到 Python 对象中?

2022-01-14 00:00:00 python parsing yaml

问题描述

如何将 YAML 文件解析/读取到 Python 对象中?

How to parse/read a YAML file into a Python object?

例如，这个 YAML:

For example, this YAML:

Person:
  name: XYZ

到这个 Python 类:

To this Python class:

class Person(yaml.YAMLObject):
  yaml_tag = 'Person'

  def __init__(self, name):
    self.name = name

顺便说一句，我正在使用 PyYAML.

I am using PyYAML by the way.

解决方案

如果你的 YAML 文件如下所示:

If your YAML file looks like this:

# tree format
treeroot:
    branch1:
        name: Node 1
        branch1-1:
            name: Node 1-1
    branch2:
        name: Node 2
        branch2-1:
            name: Node 2-1

你已经像这样安装了 PyYAML:

And you've installed PyYAML like this:

pip install PyYAML

Python 代码如下所示:

And the Python code looks like this:

import yaml
with open('tree.yaml') as f:
    # use safe_load instead load
    dataMap = yaml.safe_load(f)

变量 dataMap 现在包含一个带有树数据的字典.如果你使用 PrettyPrint 打印 dataMap，你会得到类似的东西:

The variable dataMap now contains a dictionary with the tree data. If you print dataMap using PrettyPrint, you will get something like:

{
    'treeroot': {
        'branch1': {
            'branch1-1': {
                'name': 'Node 1-1'
            },
            'name': 'Node 1'
        },
        'branch2': {
            'branch2-1': {
                'name': 'Node 2-1'
            },
            'name': 'Node 2'
        }
    }
}

所以，现在我们已经了解了如何将数据导入 Python 程序.保存数据同样简单:

So, now we have seen how to get data into our Python program. Saving data is just as easy:

with open('newtree.yaml', "w") as f:
    yaml.dump(dataMap, f)

你有一本字典，现在你必须把它转换成一个 Python 对象:

You have a dictionary, and now you have to convert it to a Python object:

class Struct:
    def __init__(self, **entries): 
        self.__dict__.update(entries)

那么你可以使用:

>>> args = your YAML dictionary
>>> s = Struct(**args)
>>> s
<__main__.Struct instance at 0x01D6A738>
>>> s...

并遵循将 Python dict 转换为对象".

有关更多信息，您可以查看 pyyaml.org 和 这个.

For more information you can look at pyyaml.org and this.

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