Re: [Zope] How to check if a string contains some characters??

12 Mar 2001

      Tino Wildenhain wrote:
...
Hi,
in pure python you can also write:
# -------------------------------------------------
import re
if re.search(r"[^A-Za-z0-9\.\-_]",string_name):
        raise Exception("illegal character here.")
# -------------------------------------------------
However this is untested. But you get the idea ;)
re is certainly faster then in-loops.
Regards
Tino
"Spicklemire, Jerry" wrote:
...
Marcello asked:
...
Is there a simple way to check if a string contain only this values:
"ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.-_"
and otherwise raise an error?
If you have a string you want to check, with the name "string_name":
<dtml-call "REQUEST.set('char_invalid', 'no')">
<dtml-let
chars_valid="'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789
.-_'">
 <dtml-while "char_valid == 'no'">
  <dtml-in string_name>
   <dtml-if "sequence-item !in chars_valid">
    <dtml-call "REQUEST.set('char_invalid', 'yes')">
   </dtml-if>
  </dtml-in>
 </dtml-while>
</dtml-let>
<dtml-if "char_invalid == 'no'">
 <dtml-call "your raise_error_code">
</dtml-if>
This may not look as simple as you want, but in pure Python,
(without alls the <dtml-stuff > this would be:
string_valid = 'yes'
for char in string_name :
        if char !in
'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789.-_' :
                string_valid = 'no'
                break
if string_valid == 'no' :
        (run your "raise error" code here)
Later,
Jerry S.
FYI:

There is no dtml-while tag.
You cannot iterate a string with dtml-in 8^(
To do this in dtml, the best thing is probably something like:

set a tokens property called allowed_chars on the folder executing the
method (or the root). This property should have all the allowed
characters in it separated by spaces. Then use this DTML (untested):

<dtml-in expr="_.range(_.len(string))">
	<dtml-unless expr="string[_['sequence-item']] in allowed_chars">
		<dtml-raise InvalidString>Invalid String</dtml-raise>
	</dtml-unless>
</dtml-in>

The performance of this would be much less than using an external python
method and regular expressions however.

-- 
| Casey Duncan
| Kaivo, Inc.
| cduncan@kaivo.com
`------------------>