Traverse JSON

|PyPI| |Build Status|

A python library for accessing and searching JSON via /slashed/paths

The package lets you traverse a JSON object as if it were a filesystem. When traversing a dictionary, a string key or or a regular expression pattern is used to traverse forward. When traversing a list, a string representation of slicing index is used to traverse forward.

sdists are available on pypi: http://pypi.python.org/pypi/traverse_json

Installing

The best way to install jsonTraverse is via easy_install or pip.

pip install traverse_json

Using jsonTraverse

import jsonTraverse

Separators

The character that should separate path components. The default is '/', but you can set it to whatever you want.

Searching JSON file

Suppose we have a JSON like this:

programmers = [
  {
    "name": "Aaron",
    "age": 21,
    "language": ["Java", "Python"]
  },
  {
    "name": "Bob",
    "age": 36,
    "language": ["C++", "Java"]
  },
  {
    "name": "Charles",
    "age": 50,
    "language": ["C++", "Fortran"]
  },
  {
    "name": "David",
    "age": 18,
    "language": ["Python"]
  },
  {
    "name": "Liam",
    "age": 42,
    "language": ["C", "Java"]
  },
  {
    "name": "Sam",
    "age": 28,
    "language": ["Java", "Python"]
  }
]

Now we want to create a list of age of all the programmers. Here is the approach we can use with traverse_json package.

>>> import traverse_json
>>> json_obj = traverse_json.JsonTraverse(json_data=programmers)
>>> path_to_age = ':/age'
>>> ages = json_obj.traverse(path_to_age, named=False)

A harder question is to find out the most popular programming language among programmers under 35 and above 35. Here is the approach we can use with traverse_json package.

>>> from six import iteritems
>>> ages = json_obj.traverse(path_to_age, named=True)
>>> paths_to_under_35 = [
      '/'.join(path.split('/')[:-1] + ['language'])
      for path, age in iteritems(ages) if age < 35
    ]
>>> paths_to_above_35 = [
      '/'.join(path.split('/')[:-1] + ['language'])
      for path, age in iteritems(ages) if age >= 35
    ]
>>> lang_under_35 = [
      lang
      for path in paths_to_under_35
      for lang in json_obj.traverse(path, named=False)[0]
    ]
>>> lang_above_35 = [
      lang
      for path in paths_to_above_35
      for lang in json_obj.traverse(path, named=False)[0]
    ]
>>> print(max(lang_under_35, key=lang_under_35.count))
>>> print(max(lang_above_35, key=lang_above_35.count))

Loading JSON

In the above example, we demonstrated loading JSON object directly. Besides, we can also load JSON from a file or from a URL. Examples are given below

>>> import traverse_json
>>> json_file = traverse_json.JsonTraverse(filepath=filepath)
>>> json_url = traverse_json.JsonTraverse(url=url)