regex - Ruby: Can't extract JSON data by nested key using group_by method -

i trying extract json objects include hotel in line1 of address, keep getting following error:

line1_hotel.rb:5:in `block in <main>': undefined method `[]' nil:nilclass (nomethoderror)     line1_hotel.rb:4:in `each'     line1_hotel.rb:4:in `group_by'     line1_hotel.rb:4:in `<main>' 

my ruby version 2.1.4p265, , code below. have used square bracket notation access data in nested keys before. in case seems failing. i've looked @ group_by ruby doc there no detail @ whether accepts kind of notation. also, if don't nest works in other examples.

require 'json'  array = json.parse file.read('gaps4.json') result = array.group_by |e|   e['address']['line1'] =~ /hotel/ ? true : false end  file.open('testtrue.json', 'w') |file|   file << json.pretty_generate(result[true]) end  file.open('testfalse.json', 'w') |file|   file << json.pretty_generate(result[false]) end 

an example "snippet" json data trying extract. example 1 object has hotel in line1 whereas other doesn't. (there many records):

[      {         "id": "242595",         "name": "san lorenzo - wimbledon",         "phone": "+442089468463",         "email": "live@sanlorenzo.com",         "website": "https://sanlorenzosw19.squarespace.com/new-page/",         "location": {           "latitude": 51.4221176,           "longitude": -0.208713,           "address": {             "line1": "38 wimbledon hill road",             "line2": "",             "line3": "",             "postcode": "sw19 7pa",             "city": "london",             "country": "uk"           }         }       },       {         "id": "101055",         "name": "sanderson",         "phone": "+442073005588",         "email": "restaurant.resuk@mhgc.com",         "website": "",         "location": {           "latitude": 51.51747,           "longitude": -0.13724,           "address": {             "line1": "sanderson hotel",             "line2": "50 berners street",             "line3": "",             "postcode": "w1t 3ng",             "city": "london",             "country": "uk"           }         }       }     ] 

e['address']['line1'] should e['location']['address']['line1']. re-check json structure.

the reason error e['address'] nil , e['address']['line1'] try call ['line'], in fact #[] method, on nil.

plus, whether not producing json yourself, fine protect code accidental errors:

e['location'] &&              # make sure location given e['location']['address'] &&   # make sure address given e['location']['address']['line1'] =~ /hotel/ ? true : false 

just not fail if no location presented.