seriattrs 2.2.0

Unofficial extension of attrs ment to provided default serialization and deserialization options

SeriArrts module for automatic serialization and deserialization

SeriArrts is an unofficial extension to attrs library. The module is ment to be used in conjunction with databases or json which may require serialization and deserialization. To allow creation of custom Object-Database mapping DbAttrs supports basic datatype such as ints, uints, vars etc.

Installation

You can install the seriattrs package using pip:

pip install seriattrs

Example

Here's an example of how to use the serialization and deserialization with SeriArrts:

@define
class Bar(DbClass):
    dictionary: dict
    date: datetime
    decimal: Decimal

@define
class Foo(DbClass):
    dictionary: dict
    date: datetime
    decimal: Decimal
    bar: Bar

foo = Foo({}, datetime.now(), Decimal(1), Bar({}, datetime.now(), Decimal(1)))
serialized = foo.get_db_representation()
foo.bar = foo.bar._id
try:
    json.dump(serialized, sys.stdout)
except:
    assert False
deserialized = Foo.from_dict(serialized)
assert deserialized == foo

Here's an example of how to use the serialization and deserialization with DbClassLiteral:

@define
class Bar(DbClassLiteral):
    dictionary: dict
    date: datetime
    decimal: Decimal

@define
class Foo(DbClass):
    dictionary: dict
    date: datetime
    decimal: Decimal
    bar: Bar

foo = Foo({}, datetime.now(), Decimal(1), Bar({}, datetime.now(), Decimal(1)))
serialized = foo.get_db_representation()
try:
    json.dump(serialized, sys.stdout)
except:
    assert False
deserialized = Foo.from_dict(serialized)
assert deserialized == foo

You can make use of db_types the following way

@define
class Foo(DbClass):
    a: int = int8()
    b: int = uint16()
    c: str = varchar(7)
    d: str = text()


class TestFooClass(unittest.TestCase):
    def setUp(self):
        self.foo_instance = Foo(0, 0, '', '')

    def test_attribute_a(self):
        with self.assertRaises(ValueError):
            self.foo_instance.a = -129  # Below int8 range
        with self.assertRaises(ValueError):
            self.foo_instance.a = 128  # Above int8 range

    def test_attribute_b_out_of_range(self):
        with self.assertRaises(ValueError):
            self.foo_instance.b = -1  # Below uint16 range
        with self.assertRaises(ValueError):
            self.foo_instance.b = 65536  # Above uint16 range

    def test_attribute_c_out_of_range(self):
        with self.assertRaises(ValueError):
            self.foo_instance.c = "Too bigg"

    def test_attribute_d_positive(self):
        passed_text = """I'm the Scatman
Ski-bi dibby dib yo da dub dub
Yo da dub dub
Ski-bi dibby dib yo da dub dub
Yo da dub dub
(I'm the Scatman)
Ski-bi dibby dib yo da dub dub
Yo da dub dub
Ski-bi dibby dib yo da dub dub
Yo da dub dub
Ba-da-ba-da-ba-be bop bop bodda bope
Bop ba bodda bope
Be bop ba bodda bope
Bop ba bodda
Ba-da-ba-da-ba-be bop ba bodda bope
Bop ba bodda bope
Be bop ba bodda bope
Bop ba bodda bope"""
        self.foo_instance.d = passed_text
        self.assertEqual(self.foo_instance.d, passed_text)