["python","json","dictionary","python-2.7"]
How to completely traverse a complex dictionary of unknown depth?

Importing from JSON can get very complex and nested structures. For example: {u'body': [{u'declarations': [{u'id': {u'name': u'i', u'type': u'Identifier'}, u'init': {u'type': u'Literal', u'value': 2}, u'type': u'VariableDeclarator'}], u'kind': u'var', u'type': u'VariableDeclaration'}, {u'declarations': [{u'id': {u'name': u'j', u'type': u'Identifier'}, u'init': {u'type': u'Literal', u'value': 4}, u'type': u'VariableDeclarator'}], u'kind': u'var', u'type': u'VariableDeclaration'}, {u'declarations': [{u'id': {u'name': u'answer', u'type': u'Identifier'}, u'init': {u'left': {u'name': u'i', u'type': u'Identifier'}, u'operator': u'*', u'right': {u'name': u'j', u'type': u'Identifier'}, u'type': u'BinaryExpression'}, u'type': u'VariableDeclarator'}], u'kind': u'var', u'type': u'VariableDeclaration'}], u'type': u'Program'} What is the recommended way to walk complex structures like the above? Apart of a few list there are mostly dictionaries, the structure can become even more imbricated so I need a general solution.
You can use a recursive generator for converting your dictionary to flat lists. def dict_generator(indict, pre=None): pre = pre[:] if pre else [] if isinstance(indict, dict): for key, value in indict.items(): if isinstance(value, dict): for d in dict_generator(value, pre + [key]): yield d elif isinstance(value, list) or isinstance(value, tuple): for v in value: for d in dict_generator(v, pre + [key]): yield d else: yield pre + [key, value] else: yield pre + [indict] It returns [u'body', u'kind', u'var'] [u'init', u'declarations', u'body', u'type', u'Literal'] [u'init', u'declarations', u'body', u'value', 2] [u'declarations', u'body', u'type', u'VariableDeclarator'] [u'id', u'declarations', u'body', u'type', u'Identifier'] [u'id', u'declarations', u'body', u'name', u'i'] [u'body', u'type', u'VariableDeclaration'] [u'body', u'kind', u'var'] [u'init', u'declarations', u'body', u'type', u'Literal'] [u'init', u'declarations', u'body', u'value', 4] [u'declarations', u'body', u'type', u'VariableDeclarator'] [u'id', u'declarations', u'body', u'type', u'Identifier'] [u'id', u'declarations', u'body', u'name', u'j'] [u'body', u'type', u'VariableDeclaration'] [u'body', u'kind', u'var'] [u'init', u'declarations', u'body', u'operator', u'*'] [u'right', u'init', u'declarations', u'body', u'type', u'Identifier'] [u'right', u'init', u'declarations', u'body', u'name', u'j'] [u'init', u'declarations', u'body', u'type', u'BinaryExpression'] [u'left', u'init', u'declarations', u'body', u'type', u'Identifier'] [u'left', u'init', u'declarations', u'body', u'name', u'i'] [u'declarations', u'body', u'type', u'VariableDeclarator'] [u'id', u'declarations', u'body', u'type', u'Identifier'] [u'id', u'declarations', u'body', u'name', u'answer'] [u'body', u'type', u'VariableDeclaration'] [u'type', u'Program']