[Zope] funny problem with tal

[Samuele Giovanni Tonon]

hi to all,
here's  the funny thing :

<meta http-equiv="refresh" content="" tal:attributes="content 
python:'2;/esami/' + context.REQUEST.SESSION['role'] + '/'">

gives a
<!-- Page Template Diagnostics
 Compilation failed
 TAL.TALDefs.TALError: Python expression error:
EOL while scanning single-quoted string (Python expression "'2", line 1)
in expression "python:'2", at line 3, column 5
-->

if i remove the ; char all is ok (but obviously the meta-http is not
working) .

is it a bug or a feature ?
is it well known ?

Regards
Samuele