moskytw / enhancedyaml

Enhanced PyYAML

It makes PyYAML more convenient and avoids duplicate YAML data.

Here are the features:

• By deafult, it uses name of class as the yaml_tag of YAMLObject.
• It loads anchor & as an attribute anchor of YAMLObject instance.
• It dumps the attribute anchor of YAMLObject instance as the anchor & name.

Examples

Here is a yaml file:

%YAML 1.1
---
examples:
    - !Example &first
        data: I am the first one.
    - !Example &second
        data: I am the second one.
order:
    - *first
    - *second

The following code is taken from test_enhanced.py.

Create an YAMLObject Without Specifiying yaml_tag

import enhancedyaml

class Example(enhancedyaml.YAMLObject): pass

Loaded YAML

Code:

from pprint import pprint

data = enhancedyaml.load(open('data/enhanced_data.yaml'))
pprint(data)

Output:

{'examples': [<__main__.Example object at 0x7fa825fb4fd0>,

              <__main__.Example object at 0x7fa825fb4cd0>],
 'order': [<__main__.Example object at 0x7fa825fb4fd0>,
           <__main__.Example object at 0x7fa825fb4cd0>]}

Content of data['order']

Code:

pprint(list(example.__dict__ for example in data['order']))

Output:

[{'anchor': u'first', 'data': 'I am the first one.'},
 {'anchor': u'second', 'data': 'I am the second one.'}]

Example has addational attribute anchor.

Dump Data Again

Code:

print enhancedyaml.dump(data, default_flow_style=False)

Output:

examples:
- &first !Example
  data: I am the first one.
- &second !Example
  data: I am the second one.
order:
- *first
- *second

It is almost same as the original YAML.

Dump Objects Which Are Generated in Runtime

Code:

e1 = Example()
e2 = Example()
e1.data = "I don't have `anchor`."
e2.data = "I don't have `anchor`, too."
es = [e1, e2, e2, e1]
print enhancedyaml.dump(es, default_flow_style=False)

Output:

- &example002 !Example
  data: I don't have `anchor`.
- &example001 !Example
  data: I don't have `anchor`, too.
- *example001
- *example002

Here are more examples.

Have fun!