smarie / python-autoclass Goto Github PK

As of today inheritance is not intuitive:

from autoclass import autoclass

@autoclass
class Foo:
    def __init__(self, foo):
        pass

@autoclass
class Bar(Foo):
    def __init__(self, bar):
        pass

yields

> ValueError: @autodict can not be set on classes that are already subclasses of Mapping, and therefore already behave like dict

In order for this to work, you have to use @autoclass(autodict=False) in the parent class. But this is not user-friendly. The proposal would be to remove this exception, and make all dict implemented methods call the corresponding super() method where appropriate

By default @autodict creates a string representation that is not very user-friendly (House({'name': 'mine', 'nb_floors': 100})).

Let's propose by default a better representation : House(name='mine', nb_floors=100)

Of course we should provide an option to fallback to legacy behaviour if users need it

This works:

from autoclass import autoclass, setter_override
from numbers import Real
from enforce import runtime_validation, config
config(dict(mode='covariant'))  # to accept subclasses in validation

@runtime_validation
@autoclass
class HouseConfiguration(object):
    def __init__(self, surface: Real):
        pass

    # -- overriden setter for surface
    @setter_override
    def surface(self, surface):
        print('Set surface to {}'.format(surface))
        self._surface = surface

t = HouseConfiguration(12)

While this throws an exception AttributeError: 'functools.partial' object has no attribute '__enforcer__':

from autoclass import autoclass, setter_override
from numbers import Real
from enforce import runtime_validation, config
config(dict(mode='covariant'))  # to accept subclasses in validation

@autoclass
@runtime_validation
class HouseConfiguration(object):
    def __init__(self, surface: Real):
        pass

    # -- overriden setter for surface
    @setter_override
    def surface(self, surface):
        print('Set surface to {}'.format(surface))
        self._surface = surface

t = HouseConfiguration(12)

The only difference is the order of the annotations on class HouseConfiguration.

When an argument is declared as optional with default value in the constructor, everytime it is set by @autoargs the setter is called twice (once with the default value and once with the value provided by the user)

global counter
counter = 0

class Home(object):
    @autoargs
    def __init__(self, foo, bar=False):
        pass

    @property
    def bar(self):
        return self._bar

    @bar.setter
    def bar(self, value):
        global counter
        counter += 1
        self._bar = value

Home(None, bar=True)
assert counter == 1  # AssertionError : counter is 2 !

Suppose I want to exclude a couple fields from the hash because for example they are not hashable.

@autoclass(autohash=False)
@autohash(exclude='bar')
class Foo:
    def __init__(self, foo: str, bar: Dict[str, str]):
        pass

The above does not work:

> a = Foo('hello', dict())
> hash(a)  # TypeError: unhashable type: 'dict'

The only workaround as of today is to use the private name associated with the attribute:

@autoclass(autohash=False)
@autohash(exclude='_bar')  # <- here use the private name
class Foo:
    def __init__(self, foo: str, bar: Dict[str, str]):
        pass

But it is not satisfying.

Note that there is probably a similar behaviour in @autodict with non-None exclude/include.

As of today, all decorators provided in autoclass source their initial attribute list on the constructor (__init__) signature.

Alternately one could wish to define the fields using pyfields:

• @autodict and @autohash would work independently
• @autoclass would also work: it would apply only @autodict and @autohash (and not @autoargs nor @autoprops as they are not anymore relevant in this context)

from autoclass import autoclass
from pyfields import field

@autoclass
class A(object):
    a = field()

As of now string representation is done by @autodict and relies on the .items() view to create the representation. It therefore can not be used independently. It would be good to propose an independent decorator for this.

I'm looking at datafiles

I like the ORM mapping of yaml that dataclasses/datafiles provides but I also love the features that python-autoclass provides, however, I can't tell if they can be used together, if they would be redundant, complementary, or if one would interfere with the other. If they can work together, would the order that the annotations are specified matter?

Edit: changed link to the actual module I would like to use.

This seems to happen with autodict on python 3.8 ? Git it from a log in valid8, did not yet reproduce it explicitly

This happens when I create a simple class and use repr on the object:

from autoclass import autoclass

@autoclass
class City:
    name: Optional[str]
    buildings: List[str] = []

>>> City("mine")

yields

  File "C:\_dev\python_ws\_Libs_OpenSource\python-autoclass\autoclass\autodict_.py", line 456, in __getitem__
    'field (was the constructor called ?)'.format(key))
KeyError: '@autodict generated dict view - args is a constructor parameter but is not a field (was the constructor called ?)'

This at least happens in autodict_.py

@autodict currently makes the class behave as a dict so that all atributes can also be accessed as dict items.

• side remark: current implementation is maybe (?) overkill for non-slots classes where there is already a __dict__ inside. This is not really an issue for now
• some (most?) users might prefer to have a as_dict or to_dict method to convert the object

When using pytypes type checker with the from_dict method generated by @autoclass/@autodict:

from pytypes import typechecked
from autoclass import autoclass

@typechecked
@autoclass
class Foo:
    def __init__(self, foo):
         pass

Foo.from_dict(dict(foo=1))

returns

pytypes.exceptions.InputTypeError: 
  classmethod autoclass.autodict.Foo.from_dict
  called with incompatible types:
Expected: Tuple[Dict]
Received: Tuple[Dict[str, int]]

@smarie Not sure if there is a way around this: In IDE (I'm using pyCharm), when using autoargs the class attribute shows up as undefined during the static checking of the IDE. It looks like this:

It would be great if there is a way to get around this issue.

Let's consider type checking with enforce with implicit optional arguments. Both of these statements succeed.

from enforce import runtime_validation

@runtime_validation
def foo(mandatory_arg: str, optional_arg: str = None):
    pass
foo('t')

@runtime_validation
class Foo:
    def __init__(self, mandatory_field: str, optional_field: str = None):
        pass
Foo('t')

However, the following fails in autoclass:

@runtime_validation
@autoclass
class Foo:
    def __init__(self, mandatory_field: str, optional_field: str = None):
        pass
a = Foo('t')
a.optional_field = None  # raises RuntimeTypeError: Argument 'val' was not of type <class 'str'>. Actual type was NoneType.

This is due to the fact that

• the PEP484 notation for Optionality has not been explicitly used (no Optional[str]), so optionality is implicitly detected by checking if there is a None default value
• however in the property setter generated by @autoprops there is no such default value >> None is therefore not considered valid

Fixing this is relatively easy: @autoprops should correctly set the __defaults__ annotation on the generated property setter.

This would perform @autoprops + @autoargs + @autodict with the same include/exclude arguments

Options would allow to disable parts of the generators, e.g. autodict=False

This would generate a def __hash__ based on the tuple of included/excluded attributes

It seems that all should also contain the names of all symbols exported by each module. Let's try to automatically generate this from public names.

Besides, it seems that the symbols imported by the package are re-exported (or at least pycharm thinks so). For example typing symbols, etc. Let's dig this topic too...

This would be just a convenience function

from autoclass import autoclass
from pytypes import typechecked
from valid8 import validate_arg, is_multiple_of
from mini_lambda import s, x, Len

@typechecked
@autoclass
class House:
    @validate_arg('name', Len(s) > 0)
    @validate_arg('surface', (x >= 0) & (x < 10000), is_multiple_of(100))
    def __init__(self, name: str, surface: int = 100):
        pass

If we create an object and then set a wrong value for the field, the exception contains a wrong reference to __init__ function:

o = House('helo')
o.surface = 150

New annotations @getters_wrapper(include, exclude) and @setters_wrapper(include, exclude), that would use @contextmanager or directly extend GeneratorContextManager in order to help users add functionality to all or some of the generated getters/setters with a function containing yield. For example in order to add a log message whenever properties are changed, the user would add a single log_property_change method to the class, decorated with @setters_wrapper.

The view should be read-only and for example either show the constructor arguments, or all fields of the object.

Hi,

I'm using python 3.5.2
The import of autoclass.autoprops raise the following error:
(ps. I updated the module typing)

Traceback (most recent call last):
  File "C:/Users/~/Desktop/test_autoclass.py", line 1, in <module>
    from autoclass import autoargs, autoprops, setter_override
  File "C:\Program Files\Anaconda3\lib\site-packages\autoclass\__init__.py", line 2, in <module>
    from autoclass.autoprops import *
  File "C:\Program Files\Anaconda3\lib\site-packages\autoclass\autoprops.py", line 169, in <module>
    def _get_getter_fun(object_type: Type, property_name: str, property_type: Optional[Type], private_property_name: str):
  File "C:\Program Files\Anaconda3\lib\typing.py", line 649, in __getitem__
    return Union[arg, type(None)]
  File "C:\Program Files\Anaconda3\lib\typing.py", line 552, in __getitem__
    dict(self.__dict__), parameters, _root=True)
  File "C:\Program Files\Anaconda3\lib\typing.py", line 512, in __new__
    for t2 in all_params - {t1} if not isinstance(t2, TypeVar)):
  File "C:\Program Files\Anaconda3\lib\typing.py", line 512, in <genexpr>
    for t2 in all_params - {t1} if not isinstance(t2, TypeVar)):
  File "C:\Program Files\Anaconda3\lib\typing.py", line 1077, in __subclasscheck__
    if super().__subclasscheck__(cls):
  File "C:\Program Files\Anaconda3\lib\abc.py", line 225, in __subclasscheck__
    for scls in cls.__subclasses__():
TypeError: descriptor '__subclasses__' of 'type' object needs an argument

#41 made it clear that a better default value for autofields could be provided when there are no other indications of fields anywhere (no explicit constructor, etc.)

Currently, only @autodict (or @autoclass with default option autodict=True) generates a __eq__ implementation, which is based on dictionary equality. It would be better to

• have an independent way of generating the equality method (@autoeq),
• and to change @autodict behaviour: rather than implementing a dictionary directly on the object, it could instead provide a as_dict() method which would be that view.

With the new valid8 4.2.1, minlens and maxlens have disappeared as they do not make sense (length is an integer by design in python, so this makes them redundant with minlen and maxlen)

The setter function generated by @autoprops has always the same argument name : 'val'.
This was primarily done so that there is no dynamic compilation, but it leads to confusing error messages when used in combination with PEP484 type checkers:

from autoclass import autoclass
from numbers import Integral

# we use enforce runtime checker for this example
from enforce import runtime_validation, config
config(dict(mode='covariant'))  # to accept subclasses in validation

@runtime_validation
@autoclass
class House:
    def __init__(self, name: str, nb_floors: Integral = 1):
        pass

obj = House('my_house', 'red')

Leads to the following error message:

enforce.exceptions.RuntimeTypeError: 
  The following runtime type errors were encountered:
       Argument 'val' was not of type <class 'numbers.Integral'>. Actual type was str.

The argument name is val in the error message, not nb_floors.

https://github.com/Stewori/pytypes seems to also provide good typechecking capabilities. Check that this is compliant with current autoclass, add a test, and update doc with an example.

This would be more consistent with autodict