Parses JSON data directly to a flat dictionary with dotted keys without parsing to Python objects first.
Given a JSON object such as:
{
"objectKey": {
"arrayKey": ["b", "c", 10, {"hello": "world"} ]
},
"someOtherKey": {
"x": 10,
"y": 12,
"z": -2.3,
"alt": null
}
}It will be parsed to following structure in Python:
{
'objectKey.arrayKey.[0]': 'b',
'objectKey.arrayKey.[1]': 'c',
'objectKey.arrayKey.[2]': 10,
'objectKey.arrayKey.[3].hello': 'world',
'someOtherKey.x': 10,
'someOtherKey.y': 12,
'someOtherKey.z': -2.3,
'someOtherKey.alt': None
}The FlatJSONParser class handles parsing the JSON string and formatting the chained keys.
>>> json_str = """{"hello": {"world": { "this is a test": "PING!" } } } """
>>> fjp = FlatJSONParser()
>>> fjp.parse(json_str)
{'hello.world.this is a test': 'PING!'}The seperator between elements in the key chains can be changed using the key_sep argument.
>>> fjp = FlatJSONParser(key_sep='|')
>>> fjp.parse(json_str)
{'hello|world|this is a test': 'PING!'}If a key in the key chain contains the key_sep string, it will be encased in the encase_dict_key pair of strings. The default is <>
>>> json_str = """{
"hello": {"world": { "this.is.a.test": "PING!" } },
"good.night": "moon."
}
"""
>>> fjp = FlatJSONParser()
>>> fjp.parse(json_str)
{'hello.world.<this.is.a.test>': 'PING!',
'<good.night>': 'moon.'}This argument can be passed either as a string of length 2, or as a tuple of strings.
>>> json_str = """{
"hello": {"world": { "this.is.a.test": "PING!" } },
"good.night": "moon."
}
"""
>>> fjp = FlatJSONParser(encase_dict_key=('<|', '|>'))
>>> fjp.parse(json_str)
{ 'hello.world.<|this.is.a.test|>': 'PING!',
'<|good.night|>': 'moon.' }The index of each element in a JSON array is added to the key chain. The default is to surround the index with the encase_list_ix string pair, the default is '[]'.
Passing an empty string or None will remove the encasement.
>>> json_str = """{ "goodnight": ["moon", "room", "cow"] } """
>>> fjp = FlatJSONParser()
>>> fjp.parse(json_str)
{'goodnight.[0]': 'moon',
'goodnight.[1]': 'room',
'goodnight.[2]': 'cow'}Arrays of objects are chained as you would expect, with the keys from the JSON ojects chaining against the array index. Here, the encase_list_ix is passed to change how
the array indices are displayed.
>>> json_str = """{ "goodnight": [{"moon": "zzz..."}, {"room": "shhhh...."}, {"cow": "moooo?"}] } """
>>> fjp = FlatJSONParser(encase_list_ix=('@', ''))
>>> fjp.parse(json_str)
{'goodnight.@0.moon': 'zzz...',
'goodnight.@1.room': 'shhhh....',
'goodnight.@2.cow': 'moooo?'}