Python Rest API - looping through dictionary object

Question

Python newbie here

I am querying an API and get a json string like this:

{
 "human": [
 {
 "h": 310,
 "prob": 0.9588886499404907,
 "w": 457,
 "x": 487,
 "y": 1053
 },
 {
 "h": 283,
 "prob": 0.8738606572151184,
 "w": 455,
 "x": 1078,
 "y": 1074
 },
 {
 "h": 216,
 "prob": 0.8639854788780212,
 "w": 414,
 "x": 1744,
 "y": 1159
 },
 {
 "h": 292,
 "prob": 0.7896996736526489,
 "w": 442,
 "x": 2296,
 "y": 1088
 }
 ]
}

I figured out how to get a dict object in python

json_data = json.loads(response.text)

But I am not sure how to loop through the dict object. I have tried this, but this prints out the key repeatedly, how do I access the parent object and child objects?

 for data in json_data:
 print data
 for sub in data:
 print sub

Answer 1

I think you want to use iteritems to get the keys and values from your dictionary like this:

for k, v in json_data.iteritems():
 print "{0} : {1}".format(k, v)

If you instead meant to traverse the dictionary recursively, try something like this:

def traverse(d):
 for k, v in d.iteritems():
 if isinstance(v, dict):
 traverse(v)
 else:
 print "{0} : {1}".format(k, v)
traverse(json_data)

• Justin D. Harris: For Python 3, use .items() instead of .iteritems().

Answer 2

See the following examples:

print json_data['human']
>> [
 {
 "h": 310,
 "prob": 0.9588886499404907,
 "w": 457,
 "x": 487,
 "y": 1053
 },
 {
 "h": 283,
 "prob": 0.8738606572151184,
 "w": 455,
 "x": 1078,
 "y": 1074
 },
 .
 .
 ]
for data in json_data['human']:
 print data
>> {
 "h": 310,
 "prob": 0.9588886499404907,
 "w": 457,
 "x": 487,
 "y": 1053
 } 
 {
 "h": 283,
 "prob": 0.8738606572151184,
 "w": 455,
 "x": 1078,
 "y": 1074
 }
.
.
for data in json_data['human']:
 print data['h']
>> 310
 283

In order to loop through the keys:

for type_ in json_data:
 print type_
 for location in json_data[type_]:
 print location

type_ is used to avoid Python's built-it type. You can use whatever name you see fit.

• Santino: Thanks, but the "key" could be different types e.g. "vehicle", "human","building" etc., how do I loop through the keys and for each of the keys loop through locations? Sorry if I wasn't clear in my original question.