I think this probably belongs on python-list instead of python-dev because python-dev is for development _of_ python, not _with_ python.
To answer your question though, there are a few tools that do this: - https://github.com/vstinner/bytecode - https://github.com/llllllllll/codetransformer I am one of the authors of codetransformer, so I am more familiar with how to use that to generate bytecode, but the bytecode project may be easier for your use case. On Thu, Oct 24, 2019 at 8:59 PM Yonatan Zunger <zun...@humu.com> wrote: > Hi everyone, > > I've found myself recently writing Python code that dynamically generates > bytecode.¹ I now have yet another case where I'm having to do this, in > which my nice situation of being able to easily precompute all the jump > addresses no longer holds. So I'm starting to write a helper to make it > easy to write bytecode from Python, with its basic API calls being > write(opcode, arg) and nextLine(optional label). The argument can be an > int, name, local name, constant, label, etc., depending on the opcode, and > it maintains all the appropriate tables and finally dumps a code object at > the end. > > All of which is well and good and makes life much easier, but... I am > *not* looking forward to writing the logic that basically duplicates that > of assemble() in compile.c, of splitting all of this into basic blocks and > computing the correct jump positions and so on before finally dumping out > the bytecode. > > Has anyone already done this that people know of? (Searching the > Internetz didn't turn anything up) Failing that, to what extent is it > reasonable to either consider assemble() as some kind of sane API point > into compile.c, and/or add some new API in compile.h which implements all > of the stuff described above in C? > > (I'm fully expecting the answer to these latter questions to be "you have > got to be kidding me," but figured it was wiser to check than to reinvent > this particular wheel if it isn't necessary) > > Yonatan > > > > ¹ Not out of masochism, in case you're wondering; there was a real use > case. A storage system would receive a read request that specified a bunch > of (key, condition) pairs, where conditions where either return any value, > return an exact value, or return values in a range. It would then receive > between 1 and 1M (depending on the request parameters) candidate cells from > the underlying storage layers, each of which had a tuple of bytes as its > actual key values; it had to compare each of those tuples against the > request parameters, and yield the values which matched. Because it's an > inner loop and can easily be called 1M times, doing this in pure Python > slows things down by a lot. Because it's also only called once, doing some > really expensive overhead like synthesizing Python code and calling > compile() on it would also slow things down a lot. But converting a bunch > of (key, condition) pairs to a really efficient function from tuples of > bytes to bools was pretty easy. > _______________________________________________ > Python-Dev mailing list -- python-dev@python.org > To unsubscribe send an email to python-dev-le...@python.org > https://mail.python.org/mailman3/lists/python-dev.python.org/ > Message archived at > https://mail.python.org/archives/list/python-dev@python.org/message/E57DTM65LFEROFZLHKRV442JPPFAWNJU/ > Code of Conduct: http://python.org/psf/codeofconduct/ >
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