[Zope] Page Template --> tal:repeat

I need to do something like this <tr tal:repeat="row python:range(value)"> But value come from another template with a form. I always have the same error: Error Type: TALESError Error Value: exceptions.NameError on global name 'value' is not defined in '', at line 14, column 5 I don't know how to solve this. I want to iterate over a sequence produced by a python script, but I can't pass an argument to the script that came from a form in another page. Thanks for any help Cristian