A few modules in the standard library have been renamed:
| Old name | New name |
|—————––|–––––––|
| _winreg | winreg |
| ConfigParser | configparser |
| copy_reg | copyreg |
| Queue | queue |
| SocketServer | socketserver |
| _markupbase | markupbase |
| repr | reprlib |
| test.test_support | test.support |
| Tkinter | tkinter |
| tkFileDialog | tkinter.filedialog |
| urllib / urllib2 | urllib, urllib.parse, urllib.error, urllib.response, urllib.request, urllib.robotparser
Some modules have even been converted from files to libraries. Take tkinter and urllib from above as an example.
When maintaining compatibility between both Python 2.x and 3.x versions, you can use the [future external package](http://python-future.org/imports.html#standard-library-imports) to enable importing top-level standard library packages with Python 3.x names on Python 2.x versions.