from sqlalchemy_querybuilder import Filter
from myapp import models, query

    rules = {
            "condition": "OR",
            "rules": [{
                       "field": "mytable.myfield",
                       "operator": "equal",
                       "value": "foo"
                       },
                      ],
             }

    myfilter = Filter(models, query)
    print(myfilter.querybuilder(rules))