Python six.get_method_self() Examples

def jump_to(self, index):
        """Immediately jump to the start of the block at the given index.

        Args:
            index (number): block index to run.
        """
        self._run_index = index

        tracer = sys.gettrace()
        if tracer:
            debugger = six.get_method_self(tracer)

            def raise_jump(*_args):
                raise JumpException(self)

            debugger.postcmd = lambda *args: True
            debugger.do_continue(None)
            sys.settrace(raise_jump)

        else:
            raise JumpException(self) 

def is_same_callback(callback1, callback2, strict=True):
    """Returns if the two callbacks are the same."""
    if callback1 is callback2:
        # This happens when plain methods are given (or static/non-bound
        # methods).
        return True
    if callback1 == callback2:
        if not strict:
            return True
        # Two bound methods are equal if functions themselves are equal and
        # objects they are applied to are equal. This means that a bound
        # method could be the same bound method on another object if the
        # objects have __eq__ methods that return true (when in fact it is a
        # different bound method). Python u so crazy!
        try:
            self1 = six.get_method_self(callback1)
            self2 = six.get_method_self(callback2)
            return self1 is self2
        except AttributeError:  # nosec
            pass
    return False 

def subscribe(func):
    '''
    Add a subscriber function to option events

    Parameters
    ----------
    func : callable
        A callable object that takes two parameters: key and value.
        This function is called with the name and value of any option
        that is set.

    Returns
    -------
    None

    '''
    if isinstance(func, types.MethodType):
        obj = six.get_method_self(func)
        func = six.get_method_function(func)
        _subscribers[func] = (weakref.ref(func), weakref.ref(obj))
    else:
        _subscribers[func] = (weakref.ref(func), None) 

def is_bound_method(ob):
    return inspect.ismethod(ob) and six.get_method_self(ob) is not None 

def get_function_path(function, bound_to=None):
    """Get received function path (as string), to import function later
    with `import_string`.
    """
    if isinstance(function, six.string_types):
        return function

    # static and class methods
    if hasattr(function, '__func__'):
        real_function = function.__func__
    elif callable(function):
        real_function = function
    else:
        return function

    func_path = []

    module = getattr(real_function, '__module__', '__main__')
    if module:
        func_path.append(module)

    if not bound_to:
        try:
            bound_to = six.get_method_self(function)
        except AttributeError:
            pass

    if bound_to:
        if isinstance(bound_to, six.class_types):
            func_path.append(bound_to.__name__)
        else:
            func_path.append(bound_to.__class__.__name__)
        func_path.append(real_function.__name__)
    else:
        # qualname is available in Python 3 only
        func_path.append(getattr(real_function, '__qualname__', real_function.__name__))

    return '.'.join(func_path) 

def is_bound_method(method):
    """Returns if the given method is bound to an object."""
    return get_method_self(method) is not None 

def get_method_self(method):
    """Gets the ``self`` object attached to this method (or none)."""
    if not inspect.ismethod(method):
        return None
    try:
        return six.get_method_self(method)
    except AttributeError:
        return None 

def get_callable_name(function):
    """Generate a name from callable.

    Tries to do the best to guess fully qualified callable name.
    """
    method_self = get_method_self(function)
    if method_self is not None:
        # This is a bound method.
        if isinstance(method_self, six.class_types):
            # This is a bound class method.
            im_class = method_self
        else:
            im_class = type(method_self)
        try:
            parts = (im_class.__module__, function.__qualname__)
        except AttributeError:
            parts = (im_class.__module__, im_class.__name__, function.__name__)
    elif inspect.ismethod(function) or inspect.isfunction(function):
        # This could be a function, a static method, a unbound method...
        try:
            parts = (function.__module__, function.__qualname__)
        except AttributeError:
            if hasattr(function, 'im_class'):
                # This is a unbound method, which exists only in python 2.x
                im_class = function.im_class
                parts = (im_class.__module__,
                         im_class.__name__, function.__name__)
            else:
                parts = (function.__module__, function.__name__)
    else:
        im_class = type(function)
        if im_class is _TYPE_TYPE:
            im_class = function
        try:
            parts = (im_class.__module__, im_class.__qualname__)
        except AttributeError:
            parts = (im_class.__module__, im_class.__name__)
    return '.'.join(parts) 

def get_class_name(obj, fully_qualified=True, truncate_builtins=True):
    """Get class name for object.

    If object is a type, returns name of the type. If object is a bound
    method or a class method, returns its ``self`` object's class name.
    If object is an instance of class, returns instance's class name.
    Else, name of the type of the object is returned. If fully_qualified
    is True, returns fully qualified name of the type. For builtin types,
    just name is returned. TypeError is raised if can't get class name from
    object.
    """
    if inspect.isfunction(obj):
        raise TypeError("Can't get class name.")

    if inspect.ismethod(obj):
        obj = get_method_self(obj)
    if not isinstance(obj, six.class_types):
        obj = type(obj)
    if truncate_builtins:
        try:
            built_in = obj.__module__ in _BUILTIN_MODULES
        except AttributeError:  # nosec
            pass
        else:
            if built_in:
                return obj.__name__
    if fully_qualified and hasattr(obj, '__module__'):
        return '%s.%s' % (obj.__module__, obj.__name__)
    else:
        return obj.__name__ 

def test_get_method_self():
    class X(object):
        def m(self):
            pass
    x = X()
    assert six.get_method_self(x.m) is x
    py.test.raises(AttributeError, six.get_method_self, 42) 

def test_get_method_self():
    class X(object):
        def m(self):
            pass
    x = X()
    assert six.get_method_self(x.m) is x
    py.test.raises(AttributeError, six.get_method_self, 42) 

def test_get_method_self():
    class X(object):
        def m(self):
            pass
    x = X()
    assert six.get_method_self(x.m) is x
    py.test.raises(AttributeError, six.get_method_self, 42) 

def handle_security(controller, im_self=None):
    """ Checks the security of a controller.  """
    if controller._pecan.get('secured', False):
        check_permissions = controller._pecan['check_permissions']

        if isinstance(check_permissions, six.string_types):
            check_permissions = getattr(
                im_self or six.get_method_self(controller),
                check_permissions
            )

        if not check_permissions():
            raise exc.HTTPUnauthorized 

def __set_parent(self, parent):
        if ismethod(parent):
            self._parent = six.get_method_self(parent)
        else:
            self._parent = parent 

def test_get_method_self():
    class X(object):
        def m(self):
            pass
    x = X()
    assert six.get_method_self(x.m) is x
    pytest.raises(AttributeError, six.get_method_self, 42) 

def _find_method(obj, func):
    if obj:
        try:
            func_self = six.get_method_self(func)
        except AttributeError:  # func has no __self__
            pass
        else:
            if func_self is obj:
                name = six.get_method_function(func).__name__
                if _is_private_method(name):
                    return _mangle_private_name(obj, func, name)
                return name
    raise ValueError("Function %s is not a method of: %s" % (func, obj)) 

def _find_method(obj, func):
    if obj:
        try:
            func_self = six.get_method_self(func)
        except AttributeError:  # func has no __self__
            pass
        else:
            if func_self is obj:
                name = six.get_method_function(func).__name__
                if _is_private_method(name):
                    return _mangle_private_name(obj, func, name)
                return name
    raise ValueError("Function %s is not a method of: %s" % (func, obj)) 

def _find_method(obj, func):
    if obj:
        try:
            func_self = six.get_method_self(func)
        except AttributeError:  # func has no __self__
            pass
        else:
            if func_self is obj:
                return six.get_method_function(func).__name__
    raise ValueError("Function %s is not a method of: %s" % (func, obj)) 

def get_method_self(method):
    """Gets the ``self`` object attached to this method (or none)."""
    if not inspect.ismethod(method):
        return None
    try:
        return six.get_method_self(method)
    except AttributeError:
        return None 

def _find_method(obj, func):
    if obj:
        try:
            func_self = six.get_method_self(func)
        except AttributeError:  # func has no __self__
            pass
        else:
            if func_self is obj:
                return six.get_method_function(func).__name__
    raise ValueError("Function %s is not a method of: %s" % (func, obj)) 

def download(self, download_func, request, spider):
        @defer.inlineCallbacks
        def process_request(request):
            for method in self.methods['process_request']:
                response = yield method(request=request, spider=spider)
                if response is not None and not isinstance(response, (Response, Request)):
                    raise _InvalidOutput('Middleware %s.process_request must return None, Response or Request, got %s' % \
                                         (six.get_method_self(method).__class__.__name__, response.__class__.__name__))
                if response:
                    defer.returnValue(response)
            defer.returnValue((yield download_func(request=request, spider=spider)))

        @defer.inlineCallbacks
        def process_response(response):
            assert response is not None, 'Received None in process_response'
            if isinstance(response, Request):
                defer.returnValue(response)

            for method in self.methods['process_response']:
                response = yield method(request=request, response=response, spider=spider)
                if not isinstance(response, (Response, Request)):
                    raise _InvalidOutput('Middleware %s.process_response must return Response or Request, got %s' % \
                                         (six.get_method_self(method).__class__.__name__, type(response)))
                if isinstance(response, Request):
                    defer.returnValue(response)
            defer.returnValue(response)

        @defer.inlineCallbacks
        def process_exception(_failure):
            exception = _failure.value
            for method in self.methods['process_exception']:
                response = yield method(request=request, exception=exception, spider=spider)
                if response is not None and not isinstance(response, (Response, Request)):
                    raise _InvalidOutput('Middleware %s.process_exception must return None, Response or Request, got %s' % \
                                         (six.get_method_self(method).__class__.__name__, type(response)))
                if response:
                    defer.returnValue(response)
            defer.returnValue(_failure)

        deferred = mustbe_deferred(process_request, request)
        deferred.addErrback(process_exception)
        deferred.addCallback(process_response)
        return deferred 

def download(self, download_func, request, spider):
        @defer.inlineCallbacks
        def process_request(request):
            for method in self.methods['process_request']:
                response = yield method(request=request, spider=spider)
                if response is not None and not isinstance(response, (Response, Request)):
                    raise _InvalidOutput('Middleware %s.process_request must return None, Response or Request, got %s' % \
                                         (six.get_method_self(method).__class__.__name__, response.__class__.__name__))
                if response:
                    defer.returnValue(response)
            defer.returnValue((yield download_func(request=request, spider=spider)))

        @defer.inlineCallbacks
        def process_response(response):
            assert response is not None, 'Received None in process_response'
            if isinstance(response, Request):
                defer.returnValue(response)

            for method in self.methods['process_response']:
                response = yield method(request=request, response=response, spider=spider)
                if not isinstance(response, (Response, Request)):
                    raise _InvalidOutput('Middleware %s.process_response must return Response or Request, got %s' % \
                                         (six.get_method_self(method).__class__.__name__, type(response)))
                if isinstance(response, Request):
                    defer.returnValue(response)
            defer.returnValue(response)

        @defer.inlineCallbacks
        def process_exception(_failure):
            exception = _failure.value
            for method in self.methods['process_exception']:
                response = yield method(request=request, exception=exception, spider=spider)
                if response is not None and not isinstance(response, (Response, Request)):
                    raise _InvalidOutput('Middleware %s.process_exception must return None, Response or Request, got %s' % \
                                         (six.get_method_self(method).__class__.__name__, type(response)))
                if response:
                    defer.returnValue(response)
            defer.returnValue(_failure)

        deferred = mustbe_deferred(process_request, request)
        deferred.addErrback(process_exception)
        deferred.addCallback(process_response)
        return deferred 

def get_callable_name(function):
    """Generate a name from callable.

    Tries to do the best to guess fully qualified callable name.
    """
    method_self = get_method_self(function)
    if method_self is not None:
        # This is a bound method.
        if isinstance(method_self, six.class_types):
            # This is a bound class method.
            im_class = method_self
        else:
            im_class = type(method_self)
        try:
            parts = (im_class.__module__, function.__qualname__)
        except AttributeError:
            parts = (im_class.__module__, im_class.__name__, function.__name__)
    elif inspect.ismethod(function) or inspect.isfunction(function):
        # This could be a function, a static method, a unbound method...
        try:
            parts = (function.__module__, function.__qualname__)
        except AttributeError:
            if hasattr(function, 'im_class'):
                # This is a unbound method, which exists only in python 2.x
                im_class = function.im_class
                parts = (im_class.__module__,
                         im_class.__name__, function.__name__)
            else:
                parts = (function.__module__, function.__name__)
    else:
        im_class = type(function)
        if im_class is _TYPE_TYPE:
            im_class = function
        try:
            parts = (im_class.__module__, im_class.__qualname__)
        except AttributeError:
            parts = (im_class.__module__, im_class.__name__)
    # When running under sphinx it appears this can be none? if so just
    # don't include it...
    mod, rest = (parts[0], parts[1:])
    if not mod:
        return '.'.join(rest)
    else:
        return '.'.join(parts) 

def _get_subscriber_key_and_value(subscriber):
        """
        Allow Subscribers to be garbage collected while still subscribed inside Publisher

        Subscribing methods of objects is tricky::

            class TheObserver(object):
                def __init__(self):
                    self.received_data = []

                def on_new_data(self, data):
                    self.received_data.append(data)

            observer1 = TheObserver()
            observer2 = TheObserver()

            subscribe(observer1.on_new_data)
            subscribe(observer2.on_new_data)
            subscribe(observer2.on_new_data)

        Even if it looks like 2 different subscriptions they all
        pass 3 different bound-method objects (different id()).
        This is so since access via observer1.on_new_data
        creates new object (bound method) on the fly.

        We want to use weakref but weakref to bound method doesn't work
        see: http://code.activestate.com/recipes/81253/
        and : https://stackoverflow.com/questions/599430/why-doesnt-the-weakref-work-on-this-bound-method
        When we wrap bound-method into weakref it may quickly disappear
        if that is only reference to bound method.
        So, we need to unbind it to have access to real method + self instance

        Unbinding above 3 examples of on_new_data will give:
        1) self                      - 2 different id()
        2) function object of class  - all 3 have same id()

        Observer key is pair: (self-id, function-id)
        """
        try:
            self_or_none = six.get_method_self(subscriber)
            self_id = instance_id(self_or_none)
            self_or_none = weakref.proxy(self_or_none)
        except AttributeError:
            self_id = 0  # default for not bound methods
            self_or_none = None

        try:
            func = six.get_method_function(subscriber)
        except AttributeError:
            func = subscriber
        function_id = instance_id(func)

        subscription_key = (self_id, function_id)
        subscription_value = (self_or_none, weakref.proxy(func))
        return subscription_key, subscription_value 

def _get_observer_key_value(observer):
        """
        Subscribing methods of objects is tricky::

            class TheObserver(object):
                def __init__(self):
                    self.received_data = []

                def on_new_data(self, data):
                    self.received_data.append(data)

            observer1 = TheObserver()
            observer2 = TheObserver()

            subscribe(observer1.on_new_data)
            subscribe(observer2.on_new_data)
            subscribe(observer2.on_new_data)

        Even if it looks like 2 different subscriptions they all
        pass 3 different bound-method objects (different id()).
        So, to differentiate them we need to "unwind" out of them:
        1) self                      - 2 different id()
        2) function object of class  - all 3 have same id()

        Observer key is pair: (self-id, function-id)
        """
        try:
            self_or_none = six.get_method_self(observer)
            self_id = instance_id(self_or_none)
            self_or_none = weakref.proxy(self_or_none)
        except AttributeError:
            self_id = 0  # default for not bound methods
            self_or_none = None

        try:
            func = six.get_method_function(observer)
        except AttributeError:
            func = observer
        function_id = instance_id(func)

        observer_key = (self_id, function_id)
        observer_value = (self_or_none, weakref.proxy(func))
        return observer_key, observer_value