python-jsonpath-rw-ext

Extensions for JSONPath RW

jsonpath-rw-ext extends json-path-rw capabilities by adding multiple extensions. 'len' that allows one to get the length of a list. 'sorted' that returns a sorted version of a list, 'arithmetic' that permits one to make math operation between elements and 'filter' to select only certain elements of a list.

Each extensions will be proposed upstream and will stay here only if they are refused.

• Free software: Apache license
• Documentation: https://python-jsonpath-rw-ext.readthedocs.org/en/latest/
• Source: http://github.com/sileht/python-jsonpath-rw-ext

Quick Start

At the command line:

$ pip install jsonpath-rw-ext

Or, if you have virtualenvwrapper installed:

$ mkvirtualenv jsonpath-rw-ext
$ pip install jsonpath-rw-ext

To replace the jsonpath_rw parser by this one with:

import jsonpath_rw_ext
jsonpath_rw_ext.parse("$.foo").find(...)

Or:

from jsonpath_rw_ext import parser
parser.ExtentedJsonPathParser().parse("$.foo").find(...)

The jsonpath classes are not part of the public API, because the name/structure can change when they will be implemented upstream. Only the syntax shouldn't change.

Extensions

name	Example
len	$.objects.`len`
sub	$.field.`sub(/foo\\+(.*)/, \\1)`
split	$.field.`split(+, 2, -1)` $.field.`split(sep, segement, maxsplit)`
sorted	$.objects.`sorted` $.objects[\some_field] $.objects[\some_field,/other_field]
filter	$.objects[?(@some_field > 5)] $.objects[?some_field = "foobar")] $.objects[?some_field > 5 & other < 2)]
arithmetic (-+*/)	$.foo + "_" + $.bar $.foo * 12 $.objects[*].cow + $.objects[*].cat

About arithmetic and string

Operations are done with python operators and allows types that python allows, and return [] if the operation can be done due to incompatible types.

When operators are used, a jsonpath must be be fully defined otherwise jsonpath-rw-ext can't known if the expression is a string or a jsonpath field, in this case it will choice string as type.

Example with data:

{
    'cow': 'foo',
    'fish': 'bar'
}

cow + fish returns cowfish

$.cow + $.fish returns foobar

$.cow + "_" + $.fish returns foo_bar

$.cow + "_" + fish returns foo_fish

About arithmetic and list

Arithmetic can be used against two lists if they have the same size.

Example with data:

{'objects': [
    {'cow': 2, 'cat': 3},
    {'cow': 4, 'cat': 6}
]}

$.objects[*].cow + $.objects[*].cat returns [6, 9]