I'm tying to create a class that holds a reference to another classes method. I want to be able to call the method. It is basically a way to do callbacks.
My code works until I try to access a class var. When I run the code below, I get the error What am I doing wrong?
Brian
import logging
class yRunMethod(object):
"""
container that allows method to be called when method run is called
"""
def __init__(self, method, *args):
"""
init
"""
self.logger = logging.getLogger('yRunMethod')
self.logger.debug('method <%s> and args <%s>'%(method, args))
self.method = method
self.args = args
def run(self):
"""
runs the method
"""
self.logger.debug('running with <%s> and <%s>'%(self.method,self.args))
#if have args sent to function
if self.args:
self.method.im_func(self.method, *self.args)
else:
self.method.im_func(self.method)
if __name__ == "__main__":
import sys
#create test class
class testClass(object):
"""
test class
"""
def __init__(self):
"""
init
"""
self.var = 'some var'
def doSomthing(self):
"""
"""
print 'do somthing called'
print 'self.var <%s>'%self.var
#test yRunMethod
met1 = testClass().doSomthing
run1 = yRunMethod(met1)
run1.run()
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Your indentation is broken. Also, where is the exception happening?Ignacio Vazquez-Abrams– Ignacio Vazquez-Abrams2010年06月04日 18:45:47 +00:00Commented Jun 4, 2010 at 18:45
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It seems like you are doing stuff similar to decorators.Felix Kling– Felix Kling2010年06月04日 20:53:36 +00:00Commented Jun 4, 2010 at 20:53
3 Answers 3
I think you're making this WAY too hard on yourself (which is easy to do ;-). Methods of classes and instances are first-class objects in Python. You can pass them around and call them like anything else. Digging into a method's instance variables is something that should almost never be done. A simple example to accomplish your goal is:
class Wrapper (object):
def __init__(self, meth, *args):
self.meth = meth
self.args = args
def runit(self):
self.meth(*self.args)
class Test (object):
def __init__(self, var):
self.var = var
def sayHello(self):
print "Hello! My name is: %s" % self.var
t = Test('FooBar')
w = Wrapper( t.sayHello )
w.runit()
1 Comment
functools.partialWhy not use this:
self.method(*self.args)
instead of this:
if self.args:
self.method.im_func(self.method, *self.args)
else:
self.method.im_func(self.method)
Comments
In your code you were calling self.method.im_func(self.method) - you shouldn't have been passing the method as argument but the object from which that method came. I.e. should have been self.method.im_func(self.method.im_self, *self.args)