This must be another newbie gotchas.
Consider the following silly code, let say I have the following in file1.py:
#============= import file2 global myBaseClass myBaseClass = file2.BaseClass() myBaseClass.AddChild(file2.NextClass()) #=============
and in file2.py, I have:
#============= global myBaseClass class BaseClass: def __init__(self): self.MyChilds = [] ... def AddChild(NewChild): self.MyChilds.append(NewChild) ... class NextClass: def __init__(self): for eachChild in myBaseClass.MyChilds: # <- ERROR ... #=============
When I run this, Python complains that myBaseClass is undefined in the last line above.
What am I doing wrong? (Yes, I know I am thinking too much in C). I thought the global declaration would have been sufficient but it's obviously not.
I think you're confused about what the global keword does. Declaring a name as global makes that name global *to the module*:
http://docs.python.org/ref/global.html http://docs.python.org/lib/built-in-funcs.html#l2h-32
What you probably want instead is:
-------------------- file1.py -------------------- import file2 myBaseClass = file2.BaseClass() myBaseClass.AddChild(file2.NextClass()) --------------------------------------------------
-------------------- file2.py --------------------
class BaseClass:
def __init__(self):
self.MyChilds = []
def AddChild(self, NewChild):
self.MyChilds.append(NewChild)
class NextClass:
def __init__(self):
from file1 import myBaseClass # IMPORT
for eachChild in myBaseClass.MyChilds:
pass
--------------------------------------------------Note that I import myBaseClass in __init__. If I imported it at the top of the module, then file1 would import file2 which would then import file1 and you'd have a circular dependency.
As it is, your code is very tightly coupled. Why don't you put all this code into a single module?
Steve -- http://mail.python.org/mailman/listinfo/python-list
