Automagic __repr__ for SQLAlchemy entities with primary key columns with Declarative Base.

gistfile1.py

# Adapted from http://foobar.lu/wp/2013/07/05/automagic-__repr__-for-sqlalchemy-entities-with-primary-key-columns-with-declarative-base/

class RepresentableBase(object):
    """
    This class can be used by ``declarative_base``, to add an automatic
    ``__repr__`` method to *all* subclasses of ``Base``. This ``__repr__`` will
    represent values as::

        ClassName(pkey_1=value_1, pkey_2=value_2, ..., pkey_n=value_n)

    where ``pkey_1..pkey_n`` are the primary key columns of the mapped table
    with the corresponding values.
    """

    def __repr__(self):
        mapper = object_mapper(self)
        items = [(p.key, getattr(self, p.key))
                 for p in [
                     mapper.get_property_by_column(c) for c in mapper.primary_key]]
        return "{0}({1})".format(
            self.__class__.__name__,
            ', '.join(['{0}={1!r}'.format(*_) for _ in items]))


Model = declarative_base(cls=RepresentableBase)