- Optional() no longer takes `default` and `null_values` arguments. These can
and should be set on the value rather than the key. This was deprecated in
0.5. Change your code as follows:
python
before
schema = Schema(
{Optional('name', default='joe', null_values=('',)): str})
after
schema = Schema(
{Optional('name'): Schema(str, default='joe', null_values=('',))})
- Falsy values such as `0`, `''`, `[]`, `{}`, False etc. are no longer
considered "null values" w.r.t. whether or not to substitute them with
a default value. If you do want these to be affected, pass them in
`null_values`. (The only value considered to be a null value by default is
None.)