title: Python - 'No module named'
body: <p>Ok, so I'm very new to programming and I'm just getting through Zed Shaw's Learn Python the Hard way.</p>
  
  <p>In the book he simply tells me to type 'import ex25', where ex25 is a file I've saved. It is saved as 'ex25.py'</p>
  
  <p>But I keep getting an error telling me that 'No module named ex25', and I have no idea why.</p>
  
  <p>I have never used the Python shell before so I'm not sure whether or not I was supposed to do something beforehand regarding directories and so on.</p>
  
  <p>Thanks.</p>