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POUsing JSON keys as attributes in nested JSON
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copied!<p>I'm working with nested JSON-like data structures in python 2.7 that I exchange with some foreign perl code. I just want to 'work with' these nested structures of lists and dictionaries in amore pythonic way.</p> <p>So if I have a structure like this...</p> <pre><code>a = { 'x': 4, 'y': [2, 3, { 'a': 55, 'b': 66 }], } </code></pre> <p>...I want to be able to deal with it in a python script as if it was nested python classes/Structs, like this:</p> <pre><code>>>> aa = j2p(a) # <<- this is what I'm after. >>> print aa.x 4 >>> aa.z = 99 >>> print a { 'x': 4, 'y': [2, 3, { 'a': 55, 'b': 66 }], 'z': 99 } >>> aa.y[2].b = 999 >>> print a { 'x': 4, 'y': [2, 3, { 'a': 55, 'b': 999 }], 'z': 99 } </code></pre> <p>Thus aa is a proxy into the original structure. This is what I came up with so far, inspired by the excellent <a href="https://stackoverflow.com/questions/100003/what-is-a-metaclass-in-python">What is a metaclass in Python?</a> question.</p> <pre><code>def j2p(x): """j2p creates a pythonic interface to nested arrays and dictionaries, as returned by json readers. >>> a = { 'x':[5,8], 'y':5} >>> aa = j2p(a) >>> aa.y=7 >>> print a {'x': [5, 8], 'y':7} >>> aa.x[1]=99 >>> print a {'x': [5, 99], 'y':7} >>> aa.x[0] = {'g':5, 'h':9} >>> print a {'x': [ {'g':5, 'h':9} , 99], 'y':7} >>> print aa.x[0].g 5 """ if isinstance(x, list): return _list_proxy(x) elif isinstance(x, dict): return _dict_proxy(x) else: return x class _list_proxy(object): def __init__(self, proxied_list): object.__setattr__(self, 'data', proxied_list) def __getitem__(self, a): return j2p(object.__getattribute__(self, 'data').__getitem__(a)) def __setitem__(self, a, v): return object.__getattribute__(self, 'data').__setitem__(a, v) class _dict_proxy(_list_proxy): def __init__(self, proxied_dict): _list_proxy.__init__(self, proxied_dict) def __getattribute__(self, a): return j2p(object.__getattribute__(self, 'data').__getitem__(a)) def __setattr__(self, a, v): return object.__getattribute__(self, 'data').__setitem__(a, v) def p2j(x): """p2j gives back the underlying json-ic json-ic nested dictionary/list structure of an object or attribute created with j2p. """ if isinstance(x, (_list_proxy, _dict_proxy)): return object.__getattribute__(x, 'data') else: return x </code></pre> <p>Now I wonder whether there is an elegant way of mapping a whole set of the <code>__*__</code> special functions, like <code>__iter__</code>, <code>__delitem__</code>? so I don't need to unwrap things using <code>p2j()</code> just to iterate or do other pythonic stuff.</p> <pre><code># today: for i in p2j(aa.y): print i # would like to... for i in aa.y: print i </code></pre>

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