Filters not implemented

Hi, thanks for your work on making a jsonpath library for Python.

I think this library might have a bug or are missing this part of the spec:

using the symbol ‘@’ for the current object. Filter expressions are supported via the syntax ?(<boolean expr>) as in

$.store.book[?(@.price < 10)].title

…

$…book[?(@.isbn)] | filter all books with isbn number $…book[?(@.price<10)] | filter all books cheapier than 10

I’m trying to filter an array by a string. My query, `$.phoneNumbers[?(@.type==‘home’)].number, works fine on the jsonpath.com testing tool, but I can’t get it working using jsonpath-ng. It fails to parse the query, complaining about the question mark.

Example code:

import json
from jsonpath_rw import jsonpath, parse

data = '''
{
  "firstName": "John",
  "lastName" : "doe",
  "age"      : 26,
  "address"  : {
    "streetAddress": "naist street",
    "city"         : "Nara",
    "postalCode"   : "630-0192"
  },
  "phoneNumbers": [
    {
      "type"  : "iPhone",
      "number": "0123-4567-8888"
    },
    {
      "type"  : "home",
      "number": "0123-4567-8910"
    }
  ]
}
'''
data = json.loads(data)
jsonpath_expr = parse(data)
jsonpath_query = "$.phoneNumbers[?(@.type=='home')].number"

Exception: JsonPathLexerError: Error on line 1, col 15: Unexpected character: ?

I’m trying this with jsonpath-rw>=1.4.0

Any ideas? Am I doing something wrong?

[hrobertson]

Just a note for those looking for negation on filtering… eg. $[?(!@.nonExistantField)] you can find it in this PR: https://github.com/h2non/jsonpath-ng/pull/21. Note you need to import parse from jsonpath_ng.ext

[dmlb2000]

and jsonpath2