strict value is overidable, in all case. (especially, __init__(strict=False), and Meta.strict=True)

[podhmo]

Current marshmallow's implementation is not allow to overwrite strict value by strict=False, when strict value is set by Meta.

class S(Schema):
    class Meta:
        strict = True

S(strict=False).strict  # => True

this pull request is the solution for #550

[podhmo]

It is a bit strange that default value of strict is None. If so, this is better, maybe.

delegated = object()

class BaseSchema(base.SchemaABC):
    .. snip
    def __init__(self, extra=None, only=(), exclude=(), prefix='', strict=delegated,
                 many=False, context=None, load_only=(), dump_only=(),
                 partial=False):

[maximkulkin]

I think there is no need for custom object as default value implementation and using None instead is OK. See my inline comments though.

[maximkulkin]

1. I think it is safe and more common not to use double underscores in test names.
2. You miss two tests when you use SchemaWithoutMeta and override with init argument (both True and False).

[podhmo]

Oh, yes I missed, adding two tests. And renaming test name (honestly, this is something like my individual habits, separating test method's name by double underscore for readability. But this is not strong will).

[maximkulkin]

👍 LGTM

Just make sure to squash your 3 commits about tests into one before merging, their commit descriptions are not informative and it is completely unnecessary to have all this small fixes in master.

[podhmo]

sure. rebased.

[sloria]

Thanks @podhmo for the PR and thanks @maximkulkin for reviewing. @podhmo : would you mind adding yourself to AUTHORS.rst? Once that's done, this is good to merge.

I consider this a bugfix, so I'll backport this to the 2.10-line branch once this is merged.

[podhmo]

added.

[sloria]

Thanks!