self=pickle.load(file)? (Object loads itself)

[Anton81]

Hi!

it seems that

class Obj:
def __init__(self):
f=file("obj.dat")
self=pickle.load(f)
....

doesn't work. Can an object load itself with pickle from a file somehow?
What's an easy solution?

Anton

[Gary Herron]

Anton81 wrote:

Hi!

it seems that

class Obj:
def __init__(self):
f=file("obj.dat")
self=pickle.load(f)
...

doesn't work. Can an object load itself with pickle from a file somehow?
What's an easy solution?

Anton

That won't work, but the following will. An object's attributes can be
accessed and set through the __dict__ attribute, and its class through
the __class__ attribute:

>>class A: # define class A

.... pass
....

>>a = A() # create an instance
a.__dict__ # It has no attributes

{}

>>a.__dict__ = {'c':1, 'b':2} # Give it some
a.b # Verify

2

>>a.c

1

>>a.__class__ # Examine its class

<class __main__.A at 0xb7da12fc>

>>class B:

.... pass
....

>>a.__class__ = B # Change its class
a.__class__ # Verify

<class __main__.B at 0xb7da129c>

Both the __dict__ and the __class__.__name__ could be pickled.

Gary Herron

[Simon Forman]

Anton81 wrote:

Hi!

it seems that

class Obj:
def __init__(self):
f=file("obj.dat")
self=pickle.load(f)
...

doesn't work. Can an object load itself with pickle from a file somehow?
What's an easy solution?

Anton

Why are you trying to do this? Usually you would just say obj =
pickle.load(f) and be done with it (you could manipulate obj after it's
created, of course.) Why do you want to do obj = Obj() but have the
obj come from "obj.dat"?

Just curious.

Peace,
~Simon