File "/home/gottfried/virtualenvs/todopyramid/todopyramid/views.py", line 205, in __call__
result = success_method(validated)
File "/home/gottfried/virtualenvs/todopyramid/todopyramid/views.py", line 307, in save_success
tags = appstruct['tags'].split(',') #optional with colander.missing, multiple tags are seperated with commas
AttributeError: 'list' object has no attribute 'split'
fixed it to work in form handling. But can be done smarter nevertheless. Form Rendering and Input Handling and Colander Schemas are very close related topics.