title: REDIS Error: WRONGTYPE Operation against a key holding the wrong kind of value
body: <p>When I store an object to Redis like this, it works fine</p>
  
  <pre><code>payload = {'age': 12}
  key = 'animals:cow'
  r.hmset(key, payload)
  </code></pre>
  
  <p>However when I create the key by joining 2 strings</p>
  
  <pre><code>payload = {'age': 12}
  key = 'animals:' + 'cow'
  r.hmset(key, payload)
  </code></pre>
  
  <p>I get the error</p>
  
  <blockquote>
    <p>redis.exceptions.ResponseError: WRONGTYPE Operation against a key holding the wrong kind of value</p>
  </blockquote>
  
  <p>Why is the second example giving an error when the <code>key</code> string is the same as in the first example?</p>