"Fuzzyman" <[EMAIL PROTECTED]> wrote in message
news:[EMAIL PROTECTED]
>
> Tim Arnold wrote:
> > "Fuzzyman" <[EMAIL PROTECTED]> wrote in message
> > news:[EMAIL PROTECTED]
> > > Hello all,
> > >
> > > I'm writing a module that takes user input as strings and
(effectively)
> > > translates them to function calls with arguments and keyword
> > > arguments.to pass a list I use a sort of 'list constructor' - so the
> > > syntax looks a bit like :
> > >
> > > checkname(arg1, "arg 2", 'arg 3', keywarg="value",
> > > keywarg2='value2', default=list("val1", 'val2'))
> > >
> > > Worst case anyway :-)
> > >
> >
> > pyparsing is great, easy to configure and very powerful--I think it
looks
> > like a great tool for your inputs.
> >
>
> Thanks - I considered it. It's actually quite a small module (about
> 38k). I don't want to introduce a dependency on an external module.
>
> All the best,
>
> Fuzzyman
> http://www.voidspace.org.uk/python/index.shtml
>
> > http://pyparsing.sourceforge.net/
> >
> >
> > --Tim
>
Fuzzy -
This wont make the pyparsing module any smaller or less external, but here's
a pyparsing grammar for you.
- handles parameter values of single or double quoted strings, numbers, or
lists
- handles nested list values
- defines the grammar in just 8 readable lines
The simple version shows the basic pyparsing code, the fancy version adds
results names, which make the results processing step simpler.
-- Paul
data = """checkname(arg1, "arg 2", 'arg 3', keywarg="value",
keywarg2='value2', default=list("val1", 'val2',list("val3.1",
'val3.2')))"""
# simple version
from pyparsing import *
ident = Word(alphas,alphanums+"_$")
fname = ident
number = Word(nums,nums+".")
listDef = Forward()
val = quotedString | number | listDef
listDef << Group( Literal("list") + "(" + delimitedList(val) + ")" )
param = Group((ident | quotedString) + Optional(Literal("=").suppress() +
val) )
fn = fname.setResultsName("func") + "(" +
Group(Optional(delimitedList(param))) + ")"
res = fn.parseString(data)
import pprint
pprint.pprint(res.asList())
prints:
['checkname',
'(',
[['arg1'],
['"arg 2"'],
["'arg 3'"],
['keywarg', '"value"'],
['keywarg2', "'value2'"],
['default',
['list',
'(',
'"val1"',
"'val2'",
['list', '(', '"val3.1"', "'val3.2'", ')'],
')']]],
')']
# fancy version, using results names
ident = Word(alphas,alphanums+"_$")
fname = ident
number = Word(nums,nums+".")
listDef = Forward()
val = quotedString | number | listDef
listDef << Group( Literal("list") + Suppress("(") + delimitedList(val) +
Suppress(")") )
noParam = object()
param = Group((ident | quotedString).setResultsName("name") + \
Optional(Literal("=").suppress() + val,
default=noParam).setResultsName("val") )
fn = fname.setResultsName("func") + "(" + \
Group(Optional(delimitedList(param))).setResultsName("params") + ")"
res = fn.parseString(data)
print "func:", res.func
print "params:"
for p in res.params:
if p.val != noParam:
print "-",p.name,"=",p.val
else:
print "-",p.name
prints:
func: checkname
params:
- arg1
- "arg 2"
- 'arg 3'
- keywarg = "value"
- keywarg2 = 'value2'
- default = ['list', '"val1"', "'val2'", ['list', '"val3.1"', "'val3.2'"]]
--
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