title: Keep getting an error for join()
body: <p>I just started learning python, and I am just trying to use the join function to combine a list to a string, but I keep getting this error</p>
  
  <pre><code>store_str = (',').join(store_hours)
    TypeError: sequence item 0: expected string, int found
  </code></pre>
  
  <p>Here is my code</p>
  
  <pre><code>time = 15
  
  store_open = None
  store_hours = [9, 10, 11, 12, 13, 14, 15, 16, 17, 18]
  store_str = (',').join(store_hours)
  </code></pre>