IndexableObject

IndexableObject is a Python class with both dictionary and attribute style accessing to it's data member.

It's serializable(pickle), iterable, and indexable.

Basic usage

IndexableObject is an object that allow it's elements to be accessed both as keys and attributes.

We create it from a dictionary or a list of dictionary, and vice versa.

>>> from indexableobject import from_dict, to_dict
>>> a = from_dict({'foo': 'bar'})
>>> a.foo
'bar'
>>> a['foo']
'bar'
to_dict(a)
{'foo': 'bar'}

Valid names

Any variable that:

is a str object,
and is an identifier (see: https://docs.python.org/3/library/stdtypes.html#str.isidentifier)
and does not both start and end with "__"

can be used as both attribute and key name.

Any hash-able object can be used as key, but not attribute name.

>>> from indexableobject import IndexableObject
>>> a = IndexableObject()
>>> a.foo = 'bar'
>>> a.foo
'bar'
>>> a['foo']
'bar'
>>> a['foo'] = 'baz'
>>> a.foo
'baz'
>>> a['foo']
'baz'
>>> a['你好'] = 'Hello'
>>> a.你好
'Hello'

Sequence

The IndexableObject can be created from Iterable/Sequence object.

We can access sequence item by it's index number:

>>> from indexableobject import from_dict
>>> a = from_dict([{'a': 'foo'}, {'a': 'bar'}])
>>> a[1].a
'bar'
>>> a[1]['a']
'bar'

Since from_dict is recursive, we can access items of a sequence inside mappings:

>>> from indexableobject import from_dict
>>> a = from_dict({'value': [{'a': 'foo'}, {'a': 'bar'}]})
>>> a['value']
[<IndexableObject object at 0x7ff7f32f4790 a='foo'>, <IndexableObject object at 0x7ff7f32f4a90 a='bar'>]
>>> a.value[0]
<IndexableObject object at 0x7ff7f32f4790 a='foo'>
>>> a.value[0].a
'foo'
>>> a.value[0]['a']
'foo'

Iterable will be converted to sequence:

>>> from indexableobject import from_dict
>>> it = range(10)
>>> a = from_dict({'range': it})
>>> a
<IndexableObject object at 0x7ff7f3bf9100 range=[0, 1, 2, 3, 4, 5, 6, 7, 8, 9]>
>>> a.range[9]
9
>>> a['range'][2]
2

Default value

A direct call to a IndexableObject object just does that:

>>> a = from_dict({'n': 1})
>>> a.n
1
>>> a['n']
1
>>> a('n')
1
>>> a('n', default=0)
1
>>> a.m
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'IndexableObject' object has no attribute 'm'
>>> a['m']
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'IndexableObject' object has no attribute 'm'
>>> a('m')
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: 'IndexableObject' object has no attribute 'm'
>>> a('m', 0)
0

Contains, iter and len

Use in operation to check if key or attribute exsisted:

>>> from indexableobject import from_dict
>>> a = from_dict({'x': object()})
>>> 'x' in a
True
>>> 'y' in a
False
>

Iterate the object will get it's all keys and attribute names, call len get it's length:

>>> from indexableobject import IndexableObject
>>> a = IndexableObject()
>>> a.hello = 'world'
>>> a[1] = 'it is 1'
>>> a
<IndexableObject object at 0x7fcd4330c100 hello='world' 1='it is 1'>
>>> list(a)
['hello', 1]
>>> len(a)
2

Update and merge

There are merge and update functions in the module:

Usage of merge:

from indexableobject import from_dict, merge
>>> a = from_dict({'x': 1})
>>> b = from_dict({'y': 2})
>>> c = merge(a, b)
>>> c
<IndexableObject object at 0x7ff7f3c63a90 x=1 y=2>
>>> a
<IndexableObject object at 0x7ff7f3c63fa0 x=1>
>>> b
<IndexableObject object at 0x7ff7f3bf9100 y=2>
>>>

Usage of update:

from indexableobject import from_dict, update
>>> update(a, b)
<IndexableObject object at 0x7ff7f3c63fa0 x=1 y=2>
>>> a
<IndexableObject object at 0x7ff7f3c63fa0 x=1 y=2>
>>> b
<IndexableObject object at 0x7ff7f3bf9100 y=2>

or you can use | , |= operator directly:

from indexableobject import from_dict
>>> a = from_dict({'x': 1})
>>> b = from_dict({'y': 2})
>>> a | b
<IndexableObject object at 0x7ff7f3ac7d60 x=1 y=2>
>>> a
<IndexableObject object at 0x7ff7f3ac7400 x=1>
>>> a|=b
>>> a
<IndexableObject object at 0x7ff7f3ac7400 x=1 y=2>