Typed named groups in regular expression

[Hugo Ferreira]

Hi!

Is it possible to "automagically" coerce the named groups to python types? e.g.:

type(re.match('(?P<x>\d*)', '123').groupdict()['x'])

<type 'str'>

But what I'm looking forward is for the type to be 'int'.

Cheers!

Hugo Ferreira

 

[Miki]

Hello Hugo,

Is it possible to "automagically" coerce the named groups to python types? e.g.:

Not that I know of, however I use the following idiom:

match = my_regexp.find(some_string)
def t(name, convert=str):
return convert(match.group(name))

myint = t("field1", int)

HTH,

 

[Paddy]

Hi!

Is it possible to "automagically" coerce the named groups to python types? e.g.:

type(re.match('(?P<x>\d*)', '123').groupdict()['x'])

<type 'str'>

But what I'm looking forward is for the type to be 'int'.

Cheers!

Hugo Ferreira

If you do a ot of that sort of thing in many programs
then it might be worth your while to set up a framework
that does it. Something like adding an underscore
then the name of a type conversion function to all
group names, and creating a function to apply the
type convertion function to all named groups of a
match object.
- Paddy.

 

[Paul McGuire]

Hi!

Is it possible to "automagically" coerce the named groups to python types? e.g.:

type(re.match('(?P<x>\d*)', '123').groupdict()['x'])

<type 'str'>

But what I'm looking forward is for the type to be 'int'.

Hugo Ferreira

If you do a ot of that sort of thing in many programs
then it might be worth your while to set up a framework
that does it. Something like adding an underscore
then the name of a type conversion function to all
group names, and creating a function to apply the
type convertion function to all named groups of a
match object.
- Paddy.

pyparsing might just be this sort of framework, in that you can attach
parse actions to elements within a grammar. At parse time, the parse
action is called with the list of tokens currently matched.

from pyparsing import Regex
re = Regex( r"(\d*)" ).setResultsName("x")\ .... .setParseAction(lambda t:int(t[0]))
results = re.parseString("123")
print results.x

123

-- Paul

 

[Hugo Ferreira]

Both Paddy (hackish) and McGuire (right tool for the job) ideas sound
very interesting ;-) I'll definitely research on them further.

Thanks for the support...

Hi!

Is it possible to "automagically" coerce the named groups to python types? e.g.:

type(re.match('(?P<x>\d*)', '123').groupdict()['x'])

<type 'str'>

But what I'm looking forward is for the type to be 'int'.

Hugo Ferreira

If you do a ot of that sort of thing in many programs
then it might be worth your while to set up a framework
that does it. Something like adding an underscore
then the name of a type conversion function to all
group names, and creating a function to apply the
type convertion function to all named groups of a
match object.
- Paddy.

pyparsing might just be this sort of framework, in that you can attach
parse actions to elements within a grammar. At parse time, the parse
action is called with the list of tokens currently matched.

from pyparsing import Regex
re = Regex( r"(\d*)" ).setResultsName("x")\ ... .setParseAction(lambda t:int(t[0]))
results = re.parseString("123")
print results.x

123

-- Paul

 

[Paddy]

Both Paddy (hackish) and McGuire (right tool for the job) ideas sound
very interesting ;-) I'll definitely research on them further.

Thanks for the support...

Hackis, hackISH!
Sir, I would have you know that the idea proffered is a hack in the
finest traditions of hackerdom.

Why, the solution is guaranteed to work for the longest time with the
smallest expenditure and be delivered in the quickest time and be good
enough - but no more.

So, promote the idea to a hack or its pistols at dawn!


- Paddy.