Examples

To demonstrate by example with the following JSON:

json = {
 'header' : {'title' : 'Hello World',
             'year' : 2014},
 'body' : { 'translations' : [
                                {'language' : 'french', 'translation' : 'bonjour'},
                                {'language' : 'german', 'translation' : 'guten tag'}
                             ]
          }
}

Traditional (pre-pson) approach:

>>> json['header']['title']
'Hello World'

New pson approach:

>>> from pson import pathquery as pq

>>> pq(json, 'header.title')
'Hello World'

Some more pson examples:

>>> from pson import pathquery as pq

>>> pq(json, 'header.title')
'Hello World'

# as you'd expect it can return sub-structures
>>> pq(json, 'body')
{'translations': [{'translation': 'bonjour', 'language': 'french'}, {'translation': 'guten tag', 'language': 'german'}]}

# and arrays
>>> pq(json, 'body.translations')
[{'translation': 'bonjour', 'language': 'french'}, {'translation': 'guten tag', 'language': 'german'}]

# you can query into arrays using numerical indicies
>>> pq(json, 'body.translations.0.language')
'french'

# you can also not specify an index and get back an array where the rest of the query
# is applied to every element in the array
>>> pq(json, 'body.translations.language')
['french', 'german']

How does it handle missing values ?

>>> from pson import pathquery as pq

# by default it returns None rather than throwing an exception
>>> pq(json, 'header.author')
None

# you can over-ride what it returns though
>>> pq(json, 'header.author', missing="Unknown")
'Unknown'

# which is useful for situations like where you're building strings and don't want to deal
# with lots of KeyError exceptions
>>> pq(json, 'header.title') + ' by ' + pq(json, 'header.author', missing="Unknown")
'Hello World by Unknown'

Installation

TBD

Authors

Built by Imran Ghory (@imranghory). Released under the MIT Licence. Contributions welcome via Github.