title: AttributeError: 'NoneType' object has no attribute 'set_acl'
body: <p>Im trying to make a file public inside a bucket but Im having this error:</p>
  
  <p>AttributeError: 'NoneType' object has no attribute 'set_acl'</p>
  
  <p>Do you see something wrong in the code?</p>
  
  <pre><code>def makeFilePublic(bucketName):
      s3 = boto.s3.connect_to_region('us-east-1') 
      bucket = s3.get_bucket(bucketName)
      key = bucket.lookup('uploadedfiles/part-00000')
      key.set_acl('public-read')
  </code></pre>