title: parse JSON values by multilevel keys
body: <p>Yesterday, I have started with learning python. I want to parse some JSON values now. I have read many of tutorials and spent a lot of time on getting values by multilevel key (if I can call it like that) in my script but nothing works to me. Can you help me please?</p>
  
  <p>This is my JSON output:</p>
  
  <pre><code>{
  "future.arte.tv": [
      {
          "mediaUrl": "http://future.arte.tv/sites/default/files/styles/desktop-span12-940x529/public/berlin.jpg?itok=CvYlNekR",
          "micropost": {
              "html": "Berlin ",
              "plainText": "Berlin"
          },
          "micropostUrl": "http://future.arte.tv/de/der-erste-weltkrieg-die-rolle-von-wissenschaft-und-technik",
          "publicationDate": "Tue Jun 17 20:31:33 CEST 2014",
          "relevance": 5.9615083,
          "timestamp": 1403029893606,
          "type": "image"
      }
  ],
  "www.zdf.de": [
      {
          "mediaUrl": "http://www.zdf.de/ZDFmediathek/contentblob/368/timg94x65blob/9800025",
          "micropost": {
              "plainText": "Berlin direkt"
          },
          "micropostUrl": "http://www.zdf.de/ZDFmediathek/hauptnavigation/sendung-a-bis-z",
          "publicationDate": "Tue Jun 10 16:25:42 CEST 2014",
          "relevance": 3.7259426,
          "timestamp": 1402410342400,
          "type": "image"
      }
  ]
  }
  </code></pre>
  
  <p>I need to get values stored in "mediaUrl" key so I tried to do</p>
  
  <pre><code>j = json.loads(jsonOutput)
  keys = j.keys(); 
  for key in keys:
      print key   # keys are future.arte.tv and www.zdf.de
      print j[key]["mediaUrl"]
  </code></pre>
  
  <p>but print j[key]["mediaUrl"] causes this error:</p>
  
  <pre><code>TypeError: list indices must be integers, not str
  </code></pre>
  
  <p>so I tried to do print j[key][0] but the result is not as I wanted to have (I want to have just mediaUrl value... btw j[key][1] causes list index out of range error):</p>
  
  <pre><code>{u'micropostUrl': u'http://www.berlin.de/special/gesundheit-und-beauty/ernaehrung/1692726-215-spargelhoefe-in-brandenburg.html', u'mediaUrl': u'http://berlin.de/binaries/asset/image_assets/42859/ratio_4_3/1371638570/170x130/', u'timestamp': 1403862143675, u'micropost': {u'plainText': u'Spargel', u'html': u'Spargel '}, u'publicationDate': u'Fri Jun 27 11:42:23 CEST 2014', u'relevance': 1.6377668, u'type': u'image'}
  </code></pre>
  
  <p>Can you give me some advice please? </p>