title: Merging two JSON strings in Python, with value lists
body: <p>I am looking to merge two JSON strings into one in Python.  string1 has identical Keys as string2, but string2 has several values in a list, like the example below:</p>
  
  <p>string1:</p>
  
  <pre><code>{'Target': 'DEV1', 'Supplier': '0', 'Message': 'A', 'Name': 'Supp1'}
  </code></pre>
  
  <p>string2:</p>
  
  <pre><code>{'Target': ['DEV2', 'DEV3'], 'Supplier': ['1', '2'], 'Message': ['B', 'C'], 'Name': ['Supp2', 'Supp3']}
  </code></pre>
  
  <p>Hopeful Merged Output string3:</p>
  
  <pre><code>{'Target': ['DEV1', 'DEV2', 'DEV3'], 'Supplier': ['0', '1', '2'], 'Message': ['A', 'B', 'C'], 'Name': ['Supp1', 'Supp2', 'Supp3']}
  </code></pre>
  
  <p>I'm not too familiar with JSON, but here's my current position:</p>
  
  <pre><code>import json
  
  str1 = json.loads(string1)
  str2 = json.loads(string2)
  
  string3 = {key, val for (key, val) in (str1.items() and str2.items())
  </code></pre>
  
  <p>The last line I found in Stackoverflow for merging JSON strings, but I am struggling with the list appending for each value.</p>
  
  <p>Any help would be greatly appreciated.</p>