Simpler version of jq

README.md

Ok jq is great but sometimes i just need to select/filter a field or two

Example usage:

$ curl https://now.httpbin.org | json now rfc3339
"2018-04-26T05:10:00.78Z"

$ echo '[{"id": 1, "title":"Hello"}, {"id": 2, "title":"Goodbye"}]' | json title=Hello id
[
  1
]

$ echo '[{"id": 1, "title":"Hello"}, {"id": 2, "title":"Goodbye"}]' | json title=Hello id
[
  1
]

$ echo '[{"id": 1, "title":"123456789"}, {"id": 2, "title":"Goodbye"}, {"id": 3, "title": "987765"}]' | json 'title~\d+' id
[
  1,
  3
]

json

#!/usr/bin/env python
import json
import sys
import re
from operator import eq

def getin(val, field):
    path = field.split('.')
    for p in path:
        if not val: return
        if isinstance(val, list) and p.isdigit() and len(v) > int(p):
            val = val[int(p)]
        elif isinstance(val, dict):
            val = val.get(p)
    return val

def matches(v, key, filter, matchfunc):
    if key.isdigit(): key = int(key)
    result = getin(v, key)
    if not result: return False
    if isinstance(result, list):
        return any(matchfunc(filter, r) for r in result)
    else:
        return matchfunc(filter, result)

def pluck(fieldspec, val):
    if ',' in fieldspec:
        fields = fieldspec.split(',')
        return {field: getin(val, field) for field in fields}
    else:
        return getin(val, fieldspec)

val = json.load(sys.stdin)
for arg in sys.argv[1:]:
    if '~' in arg:
        key, filter = arg.split('~')
        val = [v for v in val if matches(v, key, filter, re.search)]
    elif '=' in arg:
        key, filter = arg.split('=')
        val = [v for v in val if matches(v, key, filter, eq)]
    elif isinstance(val, list):
        val = [pluck(arg, v) for v in val]
    else:
        val = pluck(arg, val)

print json.dumps(val, indent=2)