NameError question - def(self,master) - master not in namespace within class?

[harijay]

Hi I am new to writing module and object oriented python code. I am
trying to understand namespaces and classes in python.

I have the following test case given in three files runner , master
and child. I am getting an error within child where in one line it
understands variable master.name and in the next line it gives a
NameError as given here

"    print "Reset name now from %s to %s , oldname %s is saved in
mastertrash" % (master.trash, master.name , master.trash)
NameError: name 'master' is not defined"


Sorry for a long post because I dont know how to  frame my question.
I am pasting the code contained in the three files and the error
message here
Thanks for your help
harijay


The detailed error I get is
hazel:tmp hari$ python runner.py
Traceback (most recent call last):
  File "runner.py", line 3, in <module>
    import child
  File "/Users/hari/rpc-ccp4/tmp/child.py", line 1, in <module>
    class child():
  File "/Users/hari/rpc-ccp4/tmp/child.py", line 9, in child
    print "Reset name now from %s to %s , oldname %s is saved in
mastertrash" % (master.trash, master.name , master.trash)
NameError: name 'master' is not defined

#File runner.py
#!/usr/bin/python
import master
import child

if __name__=="__main__":
	print "RUNNING RUNNER"
	m = master.master("hj","oldhj")
	s = child.child(m)
	print "Now I have the variable master name %s and master.trash %s" %
(m.name , m.trash)

#File master.py
class master():
	name=""
	trash=""

	def __init__(self,name,trash):
		self.name = name
		self.trash = trash


#File child.py
class child():
	def __init__(self,master):
		print "Master  name is %s" % master.name
		print  "Now seeting master name to setnameinchild in child.py "
		tmp = master.trash
		master.trash = master.name
		master.name = "setnameinchild"
     	print "Reset name now from %s to %s , oldname %s is saved in
mastertrash" % (master.trash, master.name , master.trash)