Passing a method indirectly

[swisscheese]

I'm trying to write a function that takes an arbitrary object and
method.
The function applies the method to the object (and some other stuff).
I get error "Test instance has no attribute 'method' "
How can I make this work?

def ObjApply (object,method):
object.method ()

class Test:
def test1 (self): print "Hello"
def test2 (self):
ObjApply (self,self.test1)

ta = Test ()
ta.test2 ()

[André]

swisscheese wrote:

I'm trying to write a function that takes an arbitrary object and
method.
The function applies the method to the object (and some other stuff).
I get error "Test instance has no attribute 'method' "
How can I make this work?

def ObjApply (object,method):
object.method ()

class Test:
def test1 (self): print "Hello"
def test2 (self):
ObjApply (self,self.test1)

ta = Test ()
ta.test2 ()

You need to add one line (2nd one below).

def ObjApply (object, method):
object.method = method
object.method()

class Test:
def test1 (self): print "Hello"
def test2 (self):
ObjApply (self, self.test1)

ta = Test ()
ta.test2 ()

André

[Farshid Lashkari]

You don't need to pass the object along with the method. The method is
bound to the object. Simply call the method by itself:

def ObjApply(method):
method()

class Test:
def test1 (self): print "Hello"
def test2 (self):
ObjApply(self.test1)

ta = Test ()
ta.test2 ()

If you wanted to pass an unbound method, then it would look like the
following:

def ObjApply(object,method):
method(object)

class Test:
def test1 (self): print "Hello"
def test2 (self):
ObjApply(self,Test.test1)

ta = Test ()
ta.test2 ()

[Steve Holden]

swisscheese wrote:

I'm trying to write a function that takes an arbitrary object and
method.
The function applies the method to the object (and some other stuff).
I get error "Test instance has no attribute 'method' "
How can I make this work?

def ObjApply (object,method):
object.method ()

class Test:
def test1 (self): print "Hello"
def test2 (self):
ObjApply (self,self.test1)

ta = Test ()
ta.test2 ()

Your code appears to be based on a slight misunderstanding of method
calls. In your Test class you are calling ObjApply with two arguments,
the second of which is a "bound method" (in other words, it already
implicitly references the instance of which it is a method).

In still other words, there is really no need for two arguments to
ObjApply! Perhaps you need to think through your goals more clearly ...

def ObjApply(method): ... method()
... class Test: ... def test1(self): print "Hello from", self
... def test2(self): ObjApply(self.test1)
... ts = Test()
ts.test2() Hello from <__main__.Test instance at 0x18cd238c>

So, what is it you *really* want to do?

regards
Steve
--
Steve Holden [phone] [phone]
Holden Web LLC/Ltd www.holdenweb.com
Love me, love my blog holdenweb.blogspot.com

[swisscheese]

Thanks - that worked!
Thanks to the other replies also.