[Zope] How does one display document count of a folder?

I am using a script to display the contents of a folder, but I wonder how I might display a document count of the dtml documents in a folder? Here is the script I use to display folder contents: <dtml-with my_folder> <dtml-in "objectIds()"> <a href="<dtml-var "_.getitem(_['sequence- item'],0).absolute_url()">"><dtml-var sequence-item></a><br> </dtml-in> </dtml-with> Thanks in advance!