Whats the simple way to get the information from nested JSON

Question

I've the sample JSON nested data and if I need to print out the training that each instructor teaches then how do I do that? Is there another way without using json.load()

{
   "unit":{
      "title":"training jumping",
      "raw_title":"{} training",
      "item_type":"training",
      "items":[
         {
            "_class":"training",
            "training_id":101101,
            "title":"the trainig for jumping 202",
            "instructor_details":[
               {
                  "image_100x100":"https://img-c.udemycdn.com/user/100x100/4466306_6fd8_3.jpg",
                  "instructor_id":212212,
                  "initials":"CS",
                  "display_name":"Steve Mexican",
                  "name":"Steve",
                  "_class":"user",
                  "title":"Steve Mexica"
               }
            ],

         }, 
         {
            "_class":"training",
            "training_id":121121,
            "title":"the trainig for jumping 101",
            "instructor_details":[
               {
                  "instructor_id":151151
                  "image_100x100":"https://img-c.udemycdn.com/user/100x100/4466306_6fd8_3.jpg",
                  "_class":"user"
                  "name":"Colt",
                  "initials":"CS",
                  "display_name":"Colt Steele",
                  "title":"Colt Steele"
               }
            ],

         }, 
         and more..................... data 
}

I've tried:

with open(sample.txt) as sample_file:  
training_id = re.findall(r'_class":".+?"."training_id:(\d+)', sample_file) # Creates a list with all the id 
instructor_id = re.findall(r'"instructor_details".+?"instructor_id":(\d+)', sample_file) # Creates a list with all the id 
#  don't understand here how I can match instructor_id with training_id 

Output looks like:

instructor_id >> training_id1 + training_id2.........all the training that this instructor teaches