>>> from collections import namedtuple
>>> A  = namedtuple("A", ["foo"])
>>> print(A(foo=1))
A(foo=1)
>>> str(A(foo=1))
'A(foo=1)'
>>> repr(A(foo=1))
'A(foo=1)'

def __repr__(self):
    return 'className(attrA={attrA}, attrB={attrB})'.format(**vars(self)))

from collections import namedtuple

def nice_repr(obj):
    def nice_repr(self):
        return repr(
            namedtuple(
                type(self).__name__,
                vars(self)
            )(**vars(self))
        )

    obj.__repr__ = nice_repr

    return obj

@nice_repr
class A:
    def __init__(self, b, c):
        self.b = b
        self.c = c

print(repr(A(1, 2)))  # Outputs: A(c=2, b=1)

def nice_repr(obj):
    """ Decorator to bring namedtuple's __repr__ behavior to regular classes. """

    def nice_repr(self):
        v = vars(self)

        # Prevent infinite looping if `vars` happens to include `self`.
        del(v['self'])

        return repr(namedtuple(type(self).__name__, v)(**v))

    obj.__repr__ = nice_repr

    return obj

class BaseClass:

     # logic can be used with in `__repr__` itself.
     # creating separate function to make it more clear
     def _get_formatted_string(self):
         return '{class_name}({params})'.format(
             class_name=self.__class__.__name__,
             params=', '.join('{}={}'.format(k, v) for k, v in vars(self).items()))

     def __repr__(self):
         return self._get_formatted_string()

class child(BaseClass):

    def __init__(self, a, b):
        self.a = a
        self.b = b

>>> c = child(1, 2)
>>> repr(c)
'child(a=1, b=2)'
>>> str(c)
'child(a=1, b=2)'

class Foo:
    def __init__(self):
        self.a="value"

    def __str__(self):
        return "a is: "+self.a

variable=Foo()
print variable