title: Unpacking 4-byte unsigned integers from binary file gives struct.error: unpack requires a buffer of 4 bytes
body: <p>This is a repeated question but I couldn't find answer</p>
  <p>I am reading a binary file in following format (just showing one of the 3000 lines in hex format as shown in sublime text):</p>
  <pre class="lang-none prettyprint-override"><code>0009 7f71 0009 b87b 0009 f24b 000a 2ce2
  </code></pre>
  <p>I want to read it as tuple of 4-byte unsigned integers</p>
  <pre><code>if filename:
      with open(filename, mode='rb') as file:
          fileData = file.read()
          unsignedData = struct.unpack('I', fileData )
  </code></pre>
  <p>However I get following error for last line in above code:</p>
  <pre><code>struct.error: unpack requires a buffer of 4 bytes
  </code></pre>
  <p>How to fix this?</p>