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

[Spicklemire, Jerry]

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.