title: ImportError: No module named copy_reg pickle
body: <p>I'm trying to unpickle an object stored as a blob in a MySQL database. I've manually generated and stored the pickled object in the database, but when I try to unpickle the object, I get the following rather cryptic exception:</p>
  
  <p>ImportError: No module named copy_reg</p>
  
  <p>Any ideas as to why this happens?</p>
  
  <p><strong>Method of Reproduction</strong></p>
  
  <p>Note: Must do step 1 on a Windows PC and steps 3 and 4 on a Linux PC.</p>
  
  <p>1) On a Windows PC:</p>
  
  <pre><code>file = open("test.txt", "w")
  thing = {'a': 1, 'b':2}
  cPickle.dump(thing, file)
  </code></pre>
  
  <p>2) Manually insert contents of text.txt into blob field of MySQL database running on linux</p>
  
  <p>3) In Python running on a linux machine, fetch the contents of column from MySQL</p>
  
  <p>4) Assuming that you put the contents of the blob column into a variable called data, try this:</p>
  
  <pre><code>cPickle.loads(rawString)
  </code></pre>