Dictionary Methods

A Chunk is a subclass of dict; it supports all the methods a dict does:

>>> b.keys()
['foo', 'hello']

Including update():

>>> b.update({ 'ponies': 'are pretty!' }, hello=42)
>>> print repr(b)
Chunk(foo=Chunk(lol=True), hello=42, ponies='are pretty!')

As well as iteration:

>>> [ (k,b[k]) for k in b ]
[('ponies', 'are pretty!'), ('foo', Chunk(lol=True)), ('hello', 42)]

And “splats”:

>>> "The {knights} who say {ni}!".format(**Chunk(knights='lolcats', ni='can haz'))
'The lolcats who say can haz!'

Serialization

Chunkes happily and transparently serialize to JSON and YAML.

>>> b = Chunk(foo=Chunk(lol=True), hello=42, ponies='are pretty!')
>>> import json
>>> json.dumps(b)
'{"ponies": "are pretty!", "foo": {"lol": true}, "hello": 42}'

If JSON support is present (json or simplejson), Chunk will have a toJSON() method which returns the object as a JSON string.

If you have PyYAML installed, Chunk attempts to register itself with the various YAML Representers so that Chunkes can be transparently dumped and loaded.

>>> b = Chunk(foo=Chunk(lol=True), hello=42, ponies='are pretty!')
>>> import yaml
>>> yaml.dump(b)
'!chunk.Chunk\nfoo: !chunk.Chunk {lol: true}\nhello: 42\nponies: are pretty!\n'
>>> yaml.safe_dump(b)
'foo: {lol: true}\nhello: 42\nponies: are pretty!\n'

In addition, Chunk instances will have a toYAML() method that returns the YAML string using yaml.safe_dump(). This method also replaces __str__ if present, as I find it far more readable. You can revert back to Python’s default use of __repr__ with a simple assignment: Chunk.__str__ = Chunk.__repr__. The Chunk class will also have a static method Chunk.fromYAML(), which loads a Chunk out of a YAML string.

Finally, Chunk converts easily and recursively to (unchunkify(), Chunk.toDict()) and from (chunkify(), Chunk.fromDict()) a normal dict, making it easy to cleanly serialize them in other formats.

Miscellaneous

• It is safe to import * from this module. You’ll get: Chunk, chunkify, and unchunkify.

• Ample doctests:

  $ python -m chunk.test
  $ python -m chunk.test -v | tail -n22
  1 items had no tests:
      chunk.fromYAML
  16 items passed all tests:
     8 tests in chunk
    13 tests in chunk.Chunk
     7 tests in chunk.Chunk.__contains__
     4 tests in chunk.Chunk.__delattr__
     7 tests in chunk.Chunk.__getattr__
     3 tests in chunk.Chunk.__repr__
     5 tests in chunk.Chunk.__setattr__
     2 tests in chunk.Chunk.fromDict
     2 tests in chunk.Chunk.toDict
     5 tests in chunk.chunkify
     2 tests in chunk.from_yaml
     3 tests in chunk.toJSON
     6 tests in chunk.toYAML
     3 tests in chunk.to_yaml
     3 tests in chunk.to_yaml_safe
     4 tests in chunk.unchunkify
  77 tests in 17 items.
  77 passed and 0 failed.
  Test passed.

Feedback

Open a ticket / fork the project on GitHub, or send me an email at dsc@less.ly.