A simple class decorator to define the __repr__ method based on the signature of the __init__ method.

init_repr.py

"""
A simple class decorator to define the __repr__ method  
based on the signature of the __init__ method.
"""
__author__ = 'egregius313'


_repr_template = """
def __repr__(self):
    'Return repr(self)'
    return '{cls}({kwarg_pairs})'.format(
        cls=self.__class__.__name__,
        kwarg_pairs=%s
        )
"""


def init_repr(cls):
    """
    Define __repr__ based on the call signature of __init__.
    Meant for simple types whose __init__ is

    >>> @init_repr
    ... class Person:
    ...     def __init__(self, name, age):
    ...         self.name = name
    ...         self.age = age
    ...
    >>> Person('Ed', 18)
    Person(name='Ed', age=18)
    """
    signature = inspect.signature(cls.__init__)
    parameters = list(signature.parameters.keys())[1:]
    kwargs = "', '.join('%s=%r' % (field, getattr(self, field)) for field in {fields})"
    exec(_repr_template % kwargs.format(fields=parameters))
    setattr(cls, '__repr__', eval('__repr__'))
    return cls