Basic implementation of decorators to generate default str, repr and eq for class.

decorators.py

#!/usr/bin/env python
# coding: utf-8


def _str(o):
    return "%s(%s)" % (o.__class__.__name__, ", ".join([("%s=%s" % (k, v)) for k, v in o.__dict__.items()]))

def default_str(cls):
    setattr(cls, "__str__", _str)
    return cls

def default_repr(cls):
    setattr(cls, "__repr__", _str)
    return cls

def default_eq(cls):
    def _eq(this, other):
        return this.__dict__ == other.__dict__
    setattr(cls, "__eq__", _eq)
    return cls


__all__ = ["default_str", "default_repr", "default_eq"]


if __name__ == '__main__':
    from unittest import TestCase, main

    class DecoratorsTest(TestCase):
        def testDefaultStr(self):
            @default_str
            class Foo:
                def __init__(self):
                    self.foo = "bar"

            @default_str
            class Bar:
                def __init__(self):
                    self.foo = "bar"
                    self.bar = "bazz"

            self.assertEquals("Foo(foo=bar)", str(Foo()))
            self.assertEquals("Bar(foo=bar, bar=bazz)", str(Bar()))

        def testDefaultRepr(self):
            @default_repr
            class Foo:
                def __init__(self):
                    self.var1 = "foo"
                    self.var2 = "bar"

            self.assertEquals("Foo(var1=foo, var2=bar)", repr(Foo()))

        def testDefaultEq(self):
            @default_eq
            class Foo:
                def __init__(self, var1, var2):
                    self.var1 = var1
                    self.var2 = var2

            self.assertEquals(Foo(1,2), Foo(1,2))
            self.assertNotEquals(Foo(1,2), Foo(3,4))


    main()