Python Distilled

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  • Simon Wittber
    #1

    Python Distilled

    I want to build a Python2.5 interpreter for an embedded system. I only
    have 4MB of RAM to play with, so I want to really minimise the python
    binary.

    Things I can think of removing safely are:
    - Unicode
    - Long numbers
    - Complex number
    - Compiler / Parser
    - Thread support
    - OS specific stuff

    I'd also like to remove any deprecated or stuff which is left in for
    backwards functionality (eg Classic classes).

    Google tells me that people have done this before, back in Python1.5.2
    days. Has anyone tried to do this recently with a more modern Python?

    -Sw.

    Tags: None
    • Marc 'BlackJack' Rintsch
      #2
      Re: Python Distilled

      In <1162790565.418 382.237050@m73g 2000cwd.googleg roups.com>, Simon Wittber
      wrote:
      I'd also like to remove any deprecated or stuff which is left in for
      backwards functionality (eg Classic classes).
      Classic classes are still needed for exceptions:
      >>class E(object):
      .... pass
      ....
      >>raise E
      Traceback (most recent call last):
      File "<stdin>", line 1, in <module>
      TypeError: exceptions must be classes, instances, or strings (deprecated),
      not type

      Ciao,
      Marc 'BlackJack' Rintsch

        Comment

        • Georg Brandl
          #3
          Re: Python Distilled

          Marc 'BlackJack' Rintsch wrote:
          In <1162790565.418 382.237050@m73g 2000cwd.googleg roups.com>, Simon Wittber
          wrote:
          >
          >I'd also like to remove any deprecated or stuff which is left in for
          >backwards functionality (eg Classic classes).
          >
          Classic classes are still needed for exceptions:
          >
          >>>class E(object):
          ... pass
          ...
          >>>raise E
          Traceback (most recent call last):
          File "<stdin>", line 1, in <module>
          TypeError: exceptions must be classes, instances, or strings (deprecated),
          not type
          The error is a bit misleading, since in Python 2.5 all exceptions are new-style,
          but new exception classes must be derived from an existing one.
          Classic classes, their instances and strings are only allowed for backwards
          compatibility.

          Georg

            Comment

            • Jorge Godoy
              #4
              Re: Python Distilled

              Marc 'BlackJack' Rintsch <bj_666@gmx.net writes:
              In <1162790565.418 382.237050@m73g 2000cwd.googleg roups.com>, Simon Wittber
              wrote:
              >
              >I'd also like to remove any deprecated or stuff which is left in for
              >backwards functionality (eg Classic classes).
              >
              Classic classes are still needed for exceptions:
              >
              >>>class E(object):
              ... pass
              ...
              >>>raise E
              Traceback (most recent call last):
              File "<stdin>", line 1, in <module>
              TypeError: exceptions must be classes, instances, or strings (deprecated),
              not type
              On the other hand...
              >>import exceptions
              >>class E(exceptions.Ex ception):
              .... pass
              ....
              >>raise E
              Traceback (most recent call last):
              File "<stdin>", line 1, in ?
              __main__.E
              >>>

              This also has the advantage to let it explicit in the code that E is an
              exception.


              --
              Jorge Godoy <jgodoy@gmail.c om>

                Comment

                • Paul McGuire
                  #5
                  Re: Python Distilled

                  "Marc 'BlackJack' Rintsch" <bj_666@gmx.net wrote in message
                  news:pan.2006.1 1.06.10.11.35.3 35058@gmx.net.. .
                  In <1162790565.418 382.237050@m73g 2000cwd.googleg roups.com>, Simon Wittber
                  wrote:
                  >
                  >I'd also like to remove any deprecated or stuff which is left in for
                  >backwards functionality (eg Classic classes).
                  >
                  Classic classes are still needed for exceptions:
                  >
                  >>>class E(object):
                  ... pass
                  ...
                  >>>raise E
                  Traceback (most recent call last):
                  File "<stdin>", line 1, in <module>
                  TypeError: exceptions must be classes, instances, or strings (deprecated),
                  not type
                  >
                  Ciao,
                  Marc 'BlackJack' Rintsch
                  I thought exceptions were converted to new-style classes for Py2.5
                  (http://docs.python.org/whatsnew/pep-352.html). I've not upgraded yet, so
                  cannot easily test this - under what version of Python was your posted code
                  run?

                  -- Paul


                    Comment

                    • Georg Brandl
                      #6
                      Re: Python Distilled

                      Paul McGuire wrote:
                      "Marc 'BlackJack' Rintsch" <bj_666@gmx.net wrote in message
                      news:pan.2006.1 1.06.10.11.35.3 35058@gmx.net.. .
                      >In <1162790565.418 382.237050@m73g 2000cwd.googleg roups.com>, Simon Wittber
                      >wrote:
                      >>
                      >>I'd also like to remove any deprecated or stuff which is left in for
                      >>backwards functionality (eg Classic classes).
                      >>
                      >Classic classes are still needed for exceptions:
                      >>
                      >>>>class E(object):
                      >... pass
                      >...
                      >>>>raise E
                      >Traceback (most recent call last):
                      > File "<stdin>", line 1, in <module>
                      >TypeError: exceptions must be classes, instances, or strings (deprecated),
                      >not type
                      >>
                      >Ciao,
                      >Marc 'BlackJack' Rintsch
                      >
                      I thought exceptions were converted to new-style classes for Py2.5
                      (http://docs.python.org/whatsnew/pep-352.html).
                      Yes, they were. Still, you can't raise instance of arbitrary new-style classes
                      as exceptions, and you will never be able to. In Py3k, only instances of
                      "BaseExcept ion" subclasses will be raisable.

                      Georg

                        Comment

                        • Steven Bethard
                          #7
                          Re: Python Distilled

                          Simon Wittber wrote:
                          I want to build a Python2.5 interpreter for an embedded system. I only
                          have 4MB of RAM to play with, so I want to really minimise the python
                          binary.
                          [snip]
                          Google tells me that people have done this before, back in Python1.5.2
                          days. Has anyone tried to do this recently with a more modern Python?
                          Welcome to Python.org
                          http://www.python.org/dev/summary/2006-09-16_2006-09-30/#shrinking-python
                          The official home of the Python Programming Language


                          STeVe

                            Comment

                            • Simon Wittber
                              #8
                              Re: Python Distilled

                              Welcome to Python.org
                              http://www.python.org/dev/summary/2006-09-16_2006-09-30/#shrinking-python
                              The official home of the Python Programming Language


                              Excellent, just what I was hoping for. Thanks!

                              -Sw.

                                Comment

                                • The Eternal Squire
                                  #9
                                  Re: Python Distilled

                                  Try also Diet Python on SourceForge.

                                  It's the first step toward a shrunken Python for embedded Win32
                                  systems.

                                  Cheers,

                                  The Eternal Squire


                                  Simon Wittber wrote:
                                  http://www.python.org/dev/summary/20...rinking-python
                                  >
                                  Excellent, just what I was hoping for. Thanks!
                                  >
                                  -Sw.

                                    Comment

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