title: Handling KeyError in conditional statement python when reading json file
body: <p>So I am reading through two json files to check if the keys file name and file size exist. In one of the files i only have the key filename and not file size. When running my script it keeps through a KeyError , i would like to instead make it print out the file name/names that do not have the key file size.</p>
  
  <p>The error i get is :</p>
  
  <pre><code>if data_current['File Size'] not in data_current:
  KeyError: 'File Size'
  
  
  file1.json
  
  {"File Name": "personDetails.json Exists", "File Size": "7484"}
  {"File Name": "agent.json Not Exists"}
  
  file2.json
  
  {"File Name": "personDetails.json Exists", "File Size": "7484"}
  {"File Name": "agent.json Not Exists",  "File Size": "9484"}
  </code></pre>
  
  <p>My code is as follows :</p>
  
  <pre><code>with open('file1.json', 'r') as f, open('file2.json', 'r') as g:
  
      for cd, pd in zip(f, g):
  
          data_current = json.loads(cd)
          data_previous = json.loads(pd)
          if data_current['File Size'] not in data_current:
              data_current['File Size'] = 0
  
  
          if data_current['File Name'] != data_previous['File Name']:  # If file names do not match
              print " File names do not match"
          elif data_current['File Name'] == data_previous['File Name']:  # If file names match
              print " File names match"
          elif data_current['File Size'] == data_previous['File Size']:  # If file sizes match
              print "File sizes match"
          elif data_current['File Size'] != data_previous['File Size']: # 
  
  
              print "File size is missing"
          else:
              print ("Everything is fine")
  </code></pre>