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Groups > comp.lang.python > #36114
| From | Grant Edwards <invalid@invalid.invalid> |
|---|---|
| Newsgroups | comp.lang.python |
| Subject | Re: Yet another attempt at a safe eval() call |
| Date | 2013-01-04 15:59 +0000 |
| Organization | PANIX Public Access Internet and UNIX, NYC |
| Message-ID | <kc6u8q$s34$2@reader1.panix.com> (permalink) |
| References | <kc541v$3e4$1@reader1.panix.com> <mailman.78.1357302299.2939.python-list@python.org> <50e6da35$0$30003$c3e8da3$5496439d@news.astraweb.com> |
On 2013-01-04, Steven D'Aprano <steve+comp.lang.python@pearwood.info> wrote:
> On Fri, 04 Jan 2013 07:24:04 -0500, Terry Reedy wrote:
>
>> On 1/3/2013 6:25 PM, Grant Edwards wrote:
>>>
>>> I've written a small assembler in Python 2.[67], and it needs to
>>> evaluate integer-valued arithmetic expressions in the context of a
>>> symbol table that defines integer values for a set of names. The
>>> "right" thing is probably an expression parser/evaluator using ast, but
>>> it looked like that would take more code that the rest of the assembler
>>> combined, and I've got other higher-priority tasks to get back to.
>>
>> Will ast.literal_eval do what you want?
>
> No. Grant needs to support variables, not just literal constants, hence
> the symbol table.
Right. ast.literal_eval() doesn't even support arithmetic expressions
involving only literal constats such as "3+1" (that's the bare minimum
requirement). It would also be very highly desirable to allow
expressions involving symblic constants such as "PC+1".
Google has found me exapmles of ast-based code that does pretty much
what I want, but I haven't tried it yet because of that solution's
size and complexity.
--
Grant Edwards grant.b.edwards Yow! I brought my BOWLING
at BALL -- and some DRUGS!!
gmail.com
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Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-03 23:25 +0000
Re: Yet another attempt at a safe eval() call Tim Chase <python.list@tim.thechases.com> - 2013-01-03 19:11 -0600
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 02:34 +0000
Re: Yet another attempt at a safe eval() call Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-04 07:47 +0000
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 15:53 +0000
Re: Yet another attempt at a safe eval() call Michael Torrie <torriem@gmail.com> - 2013-01-04 09:05 -0700
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 16:16 +0000
Re: Yet another attempt at a safe eval() call Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-01-05 15:56 +0000
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-06 15:12 +0000
Re: Yet another attempt at a safe eval() call Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-01-07 00:08 +0000
Re: Yet another attempt at a safe eval() call Chris Angelico <rosuav@gmail.com> - 2013-01-06 03:01 +1100
Re: Yet another attempt at a safe eval() call Oscar Benjamin <oscar.j.benjamin@gmail.com> - 2013-01-05 16:17 +0000
Re: Yet another attempt at a safe eval() call matt.newville@gmail.com - 2013-01-05 08:40 -0800
Re: Yet another attempt at a safe eval() call matt.newville@gmail.com - 2013-01-05 08:40 -0800
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 16:38 +0000
Re: Yet another attempt at a safe eval() call Chris Angelico <rosuav@gmail.com> - 2013-01-05 03:51 +1100
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 17:14 +0000
Re: Yet another attempt at a safe eval() call Chris Angelico <rosuav@gmail.com> - 2013-01-05 04:21 +1100
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 18:09 +0000
Re: Yet another attempt at a safe eval() call Chris Angelico <rosuav@gmail.com> - 2013-01-05 05:23 +1100
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 18:43 +0000
Re: Yet another attempt at a safe eval() call Chris Angelico <rosuav@gmail.com> - 2013-01-05 06:02 +1100
Re: Yet another attempt at a safe eval() call Chris Rebert <clp2@rebertia.com> - 2013-01-03 23:50 -0800
Re: Yet another attempt at a safe eval() call Terry Reedy <tjreedy@udel.edu> - 2013-01-04 07:24 -0500
Re: Yet another attempt at a safe eval() call Steven D'Aprano <steve+comp.lang.python@pearwood.info> - 2013-01-04 13:33 +0000
Re: Yet another attempt at a safe eval() call Grant Edwards <invalid@invalid.invalid> - 2013-01-04 15:59 +0000
Re: Yet another attempt at a safe eval() call Alister <alister.ware@ntlworld.com> - 2013-01-04 18:13 +0000
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