Objective

To have Twisted available on Python 3.3 and newer, with the same functionality as is currently available on Python 2.x.

Strategy

• Single source - The result will be a version of Twisted that is source-compatible with Python 2.6, Python 2.7, and Python 3.3.
• Test-driven - Following the standard Twisted development process, all changed code will be fully automatically unit tested.
• Opportunistic - Where module dependencies (within Twisted) need to be ported to support porting of the high-priority modules, modules may be split so that only some of their contents need to be ported.

All other standard Twisted development practices apply.

Details

1. Bootstrap the testing system
   1. Port the non-reactor parts of trial necessary to run the tests for the non-reactor parts of trial
      1. Refactor the implementation to separate the reactor and non-reactor parts into separate source files
      2. Add more tests for uncovered functionality
      3. Get the non-reactor parts passing their own tests on Python 3.3 (alpha, until 3.3 is actually released)
   2. Test-driven port of the dependencies of the reactor features of trial
   3. Test-driven port of the reactor features of trial
2. setup.py should only install ported modules on Python 3.
3. Test-driven port of the following modules (some of which may be dependencies of above steps):
   • twisted.cred
   • twisted.internet.defer
   • twisted.trial
   • twisted.internet.gireactor
   • twisted.internet.selectreactor
   • twisted.internet.pollreactor
   • twisted.internet.ssl
   • twisted.protocols.basic
   • twisted.web
     • client
     • http
     • resource
     • server
     • http_headers
   • twisted.internet
     • abstract
     • reactor
     • endpoints
     • protocol
     • interfaces
     • error
     • task
   • twisted.python
     • failure
     • log
     • util
     • procutils
   • twisted.names
   • twisted.application
     • internet
     • service
4. Build-slave for Python 3.3 should only run ported test modules.

• Strings
  • Python 2 largely conflates text and bytes in the str type, but offers unicode for unambiguous text usage.
  • Python 3 reduces the functionality of the str type and renames it to bytes, reflecting the intent that it be used for bytes only. It renames the unicode type to str.
  • There is a third kind of string, used to represent Python identifiers and docstrings. These are bytes in Python 2 and text in Python 3.