Bunch is a dictionary that supports attribute-style access, a la JavaScript.
>>> b = Bunch()
>>> b.hello = 'world'
>>> b.hello
'world'
>>> b['hello'] += "!"
>>> b.hello
'world!'
>>> b.foo = Bunch(lol=True)
>>> b.foo.lol
True
>>> b.foo is b['foo']
True
A Bunch 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)
Bunch(foo=Bunch(lol=True), hello=42, ponies='are pretty!')
As well as iteration:
>>> [ (k,b[k]) for k in b ]
[('ponies', 'are pretty!'), ('foo', Bunch(lol=True)), ('hello', 42)]
And "splats":
>>> "The {knights} who say {ni}!".format(**Bunch(knights='lolcats', ni='can haz'))
'The lolcats who say can haz!'
Bunches happily and transparently serialize to JSON and YAML.
>>> b = Bunch(foo=Bunch(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
), Bunch
will have a
toJSON()
method which returns the object as a JSON string.
If you have `PyYAML<http://pyyaml.org/wiki/PyYAML>`_ installed, Bunch attempts to register itself with the various YAML Representers so that Bunches can be transparently dumped and loaded.
>>> b = Bunch(foo=Bunch(lol=True), hello=42, ponies='are pretty!')
>>> import yaml
>>> yaml.dump(b)
'!bunch.Bunch\nfoo: !bunch.Bunch {lol: true}\nhello: 42\nponies: are pretty!\n'
>>> yaml.safe_dump(b)
'foo: {lol: true}\nhello: 42\nponies: are pretty!\n'
In addition, Bunch 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: Bunch.__str__ = Bunch.__repr__
. The Bunch class will also have a
static method Bunch.fromYAML()
, which loads a Bunch out of a YAML string.
Finally, Bunch converts easily and recursively to (unbunchify()
, Bunch.toDict()
) and
from (bunchify()
, Bunch.fromDict()
) a normal dict
, making it easy to cleanly
serialize them in other formats.
It is safe to
import *
from this module. You'll get:Bunch
,bunchify
, andunbunchify
.Ample doctests:
$ python -m bunch.test -v
Open a ticket at http://github.com/dsc/bunch or send me an email at [email protected] .