__dir__

[Jacek Generowicz]

Is there some way of affecting the way dir finds the information it presents?

For example, supposing a hypothetical __dir__ magic method:

class collection:
def __init__(self, myname, names):
self.names = names
self.myname = myname
def __dir__(self):
return ['%s(%s)' % (self.myname,n) for n in self.names]

class thingy:
def __init__(self, *names):
self.it = collection('it', names)

thing = thingy('this', 'that', 'theother')

dir(thing)

['__doc__', '__init__', '__module__', 'it(this)', 'it(that)', 'it(theother)']


In other words, I would like some attributes of an instance to inject
some information into the output of dir ... to change the way their
names are perceived by dir.

Any ideas ?

 

[Peter Otten]

Is there some way of affecting the way dir finds the information it
presents?

For example, supposing a hypothetical __dir__ magic method:

class collection:
def __init__(self, myname, names):
self.names = names
self.myname = myname
def __dir__(self):
return ['%s(%s)' % (self.myname,n) for n in self.names]

class thingy:
def __init__(self, *names):
self.it = collection('it', names)

thing = thingy('this', 'that', 'theother')

dir(thing)

['__doc__', '__init__', '__module__', 'it(this)', 'it(that)',
['it(theother)']


In other words, I would like some attributes of an instance to inject
some information into the output of dir ... to change the way their
names are perceived by dir.

Any ideas ?

.... __members__ = ["Is this evil?", "So what"]
....

dir(C) ['__doc__', '__members__', '__module__']
dir(C()) ['Is this evil?', 'So what', '__doc__', '__members__', '__module__']

However, __members__ is marked as deprecated and, even more important, I
don't know what the side effects of the above may be.
Highly unrecommended.

Peter

 

[Jacek Generowicz]

However, __members__ is marked as deprecated and, even more important, I
don't know what the side effects of the above may be.
Highly unrecommended.

Great, sounds just perfect for my needs ;-)