title: Function object is not iterable
body: <p><a href="https://stackoverflow.com/questions/3431825/generating-a-md5-checksum-of-a-file">Generating an MD5 checksum of a file</a></p>
  
  <p>I have used one of the examples from the above link but made some a small change to it by removing the call to the function (originally from above):</p>
  
  <pre><code>import hashlib
  hash = hashlib.md5()
  with open('validFilePath/file.xxx', "r+b") as f:
      for block in iter(lambda: f.read(65536), ""):
          hash.update(block)
  return hash.hexdigest()
  </code></pre>
  
  <p>This gives me the following error. </p>
  
  <pre><code>File "&lt;string&gt;", line 4, in &lt;module&gt;
  TypeError: 'function' object is not iterable
  </code></pre>
  
  <p>Am I missing some basic Python premise?</p>