[ZPT] Trouble understanding syntax for accessing modules from ZPT's

[Lynn Walton]

I'm trying to access the DocumentTemplate/sequence/SortEx module from a
ZPT and I've tried about every variation I can think of: and can't get
it.

If I try something like:
<span tal:define="global sort python:
modules/DocumentTemplate.sequence"></span>

I get:

  File
/opt/WWW/ZopeInstallation/InstanceHome/Products/PageTemplates/ZRPythonExpr.py,
line 121, in __call__
    (Info: modules/DocumentTemplate.sequence)
  File Python expression "modules/DocumentTemplate.sequence", line 2, in
f
    (Object: guarded_getattr)
TALESError: Sorry, an error occurred

When I try without python: in it,
<span tal:define="global sort
modules/DocumentTemplate.sequence"></span>
I get asked for basic authentication even though I'm logged in as
manager.

Thanks for any help,
Lynn