Re: String to valid Python identifier

[Vlastimil Brom]

2009/8/8 Дамјан Георгиевски :
>
>
>>> Is there any easy function in the stdlib to convert any random string
>>> in a valid Python identifier .. possibly by replacing non-valid
>>> characters with _ ?
...
>
> ps.
> by "convert" I didn't mean a full transformation... I was more hoping
> for the least intrusive transformation that would still leave
> discernible resemblance of the original string.
>
>
>
> --
> дамјан ( http://softver.org.mk/damjan/ )
>
> When you do things right, people won't be sure if you did anything at
> all.
> --
> http://mail.python.org/mailman/listinfo/python-list
>

Depending on the needs (speed, readability ...), the regular
expression replacement might be viable too:
>>> import re
>>> print re.sub(r"[^a-zA-Z0-9_]", r"_", u"aábc d:eé_123's - foo?!var")
a_bc_d_e__123_s___foo__var
>>> print re.sub(r"\W", r"_", u"aábc d:eé_123's - foo?!var") # equivalent
a_bc_d_e__123_s___foo__var
>>>

Additionally, as with the other approaches, you also have to check for
the (illegal) starting digit and replace it or prepend some valid
prefix.
hth
 vbr
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Re: String to valid Python identifier

[Дамјан Георгиевски]

>> Is there any easy function in the stdlib to convert any random string
>> in a valid Python identifier .. possibly by replacing non-valid
>> characters with _ ?
> 
> I think this is fairly underspecified as a problem statement. A
> solution that would meet your specification would be

True, I was thinking that if there was an obvious solution I'd get the 
answer right away.. so it seems there's not.

I did try the string.maketrans way... it was a bit ugly so I decided to 
ask here if I'm missing something... maybe I'll try maketrans again.


ps.
by "convert" I didn't mean a full transformation... I was more hoping 
for the least intrusive transformation that would still leave 
discernible resemblance of the original string. 



-- 
дамјан ( http://softver.org.mk/damjan/ )

When you do things right, people won't be sure if you did anything at 
all.
-- 
http://mail.python.org/mailman/listinfo/python-list

Re: String to valid Python identifier

[Martin v. Löwis]

> Is there any easy function in the stdlib to convert any random string in 
> a valid Python identifier .. possibly by replacing non-valid characters 
> with _ ?

I think this is fairly underspecified as a problem statement. A solution
that would meet your specification would be

def mkident(s):
return "foo"

It returns a valid Python identifier for any random string.

If you now complain that this gives too many collisions, I propose

def mkident(s):
return "foo%d" % (hash(s) & 0x7fff)

Regards,
Martin
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Re: String to valid Python identifier

[MRAB]

Дамјан Георгиевски wrote:
Is there any easy function in the stdlib to convert any random string in 
a valid Python identifier .. possibly by replacing non-valid characters 
with _ ?


Python 2.x only, so no need to do Unicode.


Lookup the 'maketrans' function in the 'string' module and the
'translate' method of the 'str' class.
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String to valid Python identifier

[Дамјан Георгиевски]

Is there any easy function in the stdlib to convert any random string in 
a valid Python identifier .. possibly by replacing non-valid characters 
with _ ?

Python 2.x only, so no need to do Unicode.


-- 
дамјан ( http://softver.org.mk/damjan/ )

Religion ends and philosophy begins, 
just as alchemy ends and chemistry begins 
and astrology ends, and astronomy begins.
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