Generate random JSON structure permutations for a data set

Question

I want to generate many different permutations of JSON structures as a representation of the same data set, preferably without having to hard code the implementation. For example, given the following JSON:

{"name": "smith", "occupation": "agent", "enemy": "humanity", "nemesis": "neo"}`

Many different permutations should be produced, such as:

• change in name : {"name":"smith"}- > {"last_name":"smith"}
• change in order: {"name":"...","occupation":"..."} -> {"occupation":"...", "name":"..."}
• change in arrangement: {"name":"...","occupation":"..."} -> "smith":{"occupation":"..."}
• change in template: {"name":"...","occupation":"..."} -> "status": 200, "data":{"name":"...","occupation":"..."}
• etc.

Currently, the implementation is as follows:

I am using itertools.permutations and OrderedDict() to range through the possible key and respective value combinations as well as the order in which they are returned.

key_permutations = SchemaLike(...).permutate()

all_simulacrums = []
for key_permutation in key_permutations:
   simulacrums = OrderedDict(key_permutation)
   all_simulacrums.append(simulacrums)
for x in itertools.permutations(all_simulacrums.items()):
    test_data = json.dumps(OrderedDict(p))
    print(test_data)
    assert json.loads(test_data) == data, 'Oops! {} != {}'.format(test_data, data)

My problem occurs when I try to implement the permutations of arrangement and template. I don't know how best to implement this functionality, any suggestions?

Answer 1

For ordering, just use ordered dicts:

>>> data = OrderedDict(foo='bar', bacon='eggs', bar='foo', eggs='bacon')
>>> for p in itertools.permutations(data.items()):
...     test_data = json.dumps(OrderedDict(p))
...     print(test_data)
...     assert json.loads(test_data) == data, 'Oops! {} != {}'.format(test_data, data)

{"foo": "bar", "bacon": "eggs", "bar": "foo", "eggs": "bacon"}
{"foo": "bar", "bacon": "eggs", "eggs": "bacon", "bar": "foo"}
{"foo": "bar", "bar": "foo", "bacon": "eggs", "eggs": "bacon"}
{"foo": "bar", "bar": "foo", "eggs": "bacon", "bacon": "eggs"}
{"foo": "bar", "eggs": "bacon", "bacon": "eggs", "bar": "foo"}
{"foo": "bar", "eggs": "bacon", "bar": "foo", "bacon": "eggs"}
{"bacon": "eggs", "foo": "bar", "bar": "foo", "eggs": "bacon"}
{"bacon": "eggs", "foo": "bar", "eggs": "bacon", "bar": "foo"}
{"bacon": "eggs", "bar": "foo", "foo": "bar", "eggs": "bacon"}
{"bacon": "eggs", "bar": "foo", "eggs": "bacon", "foo": "bar"}
{"bacon": "eggs", "eggs": "bacon", "foo": "bar", "bar": "foo"}
{"bacon": "eggs", "eggs": "bacon", "bar": "foo", "foo": "bar"}
{"bar": "foo", "foo": "bar", "bacon": "eggs", "eggs": "bacon"}
{"bar": "foo", "foo": "bar", "eggs": "bacon", "bacon": "eggs"}
{"bar": "foo", "bacon": "eggs", "foo": "bar", "eggs": "bacon"}
{"bar": "foo", "bacon": "eggs", "eggs": "bacon", "foo": "bar"}
{"bar": "foo", "eggs": "bacon", "foo": "bar", "bacon": "eggs"}
{"bar": "foo", "eggs": "bacon", "bacon": "eggs", "foo": "bar"}
{"eggs": "bacon", "foo": "bar", "bacon": "eggs", "bar": "foo"}
{"eggs": "bacon", "foo": "bar", "bar": "foo", "bacon": "eggs"}
{"eggs": "bacon", "bacon": "eggs", "foo": "bar", "bar": "foo"}
{"eggs": "bacon", "bacon": "eggs", "bar": "foo", "foo": "bar"}
{"eggs": "bacon", "bar": "foo", "foo": "bar", "bacon": "eggs"}
{"eggs": "bacon", "bar": "foo", "bacon": "eggs", "foo": "bar"}

The same principle can be applied for key/value permutations:

>>> for p in itertools.permutations(data.keys()):
...:     test_data = json.dumps(OrderedDict(zip(p, data.values())))
...:     print(test_data)
...:     
{"foo": "bar", "bacon": "eggs", "bar": "foo", "eggs": "bacon"}
{"foo": "bar", "bacon": "eggs", "eggs": "foo", "bar": "bacon"}
{"foo": "bar", "bar": "eggs", "bacon": "foo", "eggs": "bacon"}
{"foo": "bar", "bar": "eggs", "eggs": "foo", "bacon": "bacon"}
{"foo": "bar", "eggs": "eggs", "bacon": "foo", "bar": "bacon"}
{"foo": "bar", "eggs": "eggs", "bar": "foo", "bacon": "bacon"}
{"bacon": "bar", "foo": "eggs", "bar": "foo", "eggs": "bacon"}
{"bacon": "bar", "foo": "eggs", "eggs": "foo", "bar": "bacon"}
{"bacon": "bar", "bar": "eggs", "foo": "foo", "eggs": "bacon"}
{"bacon": "bar", "bar": "eggs", "eggs": "foo", "foo": "bacon"}
{"bacon": "bar", "eggs": "eggs", "foo": "foo", "bar": "bacon"}
{"bacon": "bar", "eggs": "eggs", "bar": "foo", "foo": "bacon"}
{"bar": "bar", "foo": "eggs", "bacon": "foo", "eggs": "bacon"}
{"bar": "bar", "foo": "eggs", "eggs": "foo", "bacon": "bacon"}
{"bar": "bar", "bacon": "eggs", "foo": "foo", "eggs": "bacon"}
{"bar": "bar", "bacon": "eggs", "eggs": "foo", "foo": "bacon"}
{"bar": "bar", "eggs": "eggs", "foo": "foo", "bacon": "bacon"}
{"bar": "bar", "eggs": "eggs", "bacon": "foo", "foo": "bacon"}
{"eggs": "bar", "foo": "eggs", "bacon": "foo", "bar": "bacon"}
{"eggs": "bar", "foo": "eggs", "bar": "foo", "bacon": "bacon"}
{"eggs": "bar", "bacon": "eggs", "foo": "foo", "bar": "bacon"}
{"eggs": "bar", "bacon": "eggs", "bar": "foo", "foo": "bacon"}
{"eggs": "bar", "bar": "eggs", "foo": "foo", "bacon": "bacon"}
{"eggs": "bar", "bar": "eggs", "bacon": "foo", "foo": "bacon"}

And so on... You can just use a predefined set of keys/values if you don't need all combinations. You can also use a for loop with random.choice to flip a coin in order to skip some combinations or use random.shuffle at the risk of repeating combinations.

For the template thing I guess you must create a list (or a list of lists if you want nested structures) of different templates and then iterate over it in order to create your data. In order to give a better suggestion we need a more constrained specification of what you want.

Note that there are several libraries that generate test data in Python:

>>> from faker import Faker
>>> faker = Faker()
>>> faker.credit_card_full().strip().split('\n')
['VISA 13 digit', 'Jerry Gutierrez', '4885274641760 04/24', 'CVC: 583']

Faker has several schemas and it is easy to create your own custom fake data providers.