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

Question

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

For example, this YAML:

Person:   name: XYZ 

To this Python class:

class Person(yaml.YAMLObject):   yaml_tag = 'Person'    def __init__(self, name):     self.name = name 

I am using PyYAML by the way.

Answer 1

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 

And you've installed PyYAML like this:

pip install PyYAML 

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) 

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'         }     } } 

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) 

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) 

Then you can use:

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

and follow "Convert Python dict to object".

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