SQLAlchemy - build query filter dynamically from dict

So I have a dict passed from a web page. I want to build the query dynamically based on the dict. I know I can do:

session.query(myClass).filter_by(**web_dict)

However, that only works when the values are an exact match. I need to do 'like' filtering. My best attempt using the __dict__ attribute:

for k,v in web_dict.items():
    q = session.query(myClass).filter(myClass.__dict__[k].like('%%%s%%' % v))

Not sure how to build the query from there. Any help would be awesome.