listing all property variables of a class instance

[=?iso-8859-1?B?QW5kcuk=?=]

Suppose I define a class with a number of variables defined as
properties. Something like:

class MyClass(object):

def __init__(self):
self.some_variable = 42
self._a = None
self._b = "pi"

def get_a(self):
return self._a
def set_a(self, value):
self._a = value

def get_b(self):
return self._b
def set_b(self, value):
self._b = value

a = property(get_a, set_a, None, "a is a property")
b = property(get_b, set_b, None, "b is a property")

Is there a way to write a method that would list automatically all the
variables defined as a property (say by printing their docstring and/
or their value), and only those variables?

André

 

[Neil Cerutti]

Suppose I define a class with a number of variables defined as
properties. Something like:

class MyClass(object):

def __init__(self):
self.some_variable = 42
self._a = None
self._b = "pi"

def get_a(self):
return self._a
def set_a(self, value):
self._a = value

def get_b(self):
return self._b
def set_b(self, value):
self._b = value

a = property(get_a, set_a, None, "a is a property")
b = property(get_b, set_b, None, "b is a property")

Is there a way to write a method that would list automatically
all the variables defined as a property (say by printing their
docstring and/ or their value), and only those variables?

This is off the cuff. There's likely a better way.

for k, v in MyClass.__dict__.iteritems():
if isinstance(v, property):
print k, v.__doc__

 

[Jay Loden]

This is off the cuff. There's likely a better way.

for k, v in MyClass.__dict__.iteritems():
if isinstance(v, property):
print k, v.__doc__

The only way I could get this to work was to change the way the properties were defined/initalized:

#!/usr/bin/python

class MyClass(object):

def __init__(self):
self.some_variable = 42
self._a = None
self._b = "pi"
self.a = property(self.get_a, self.set_a, None, "a is a property")
self.b = property(self.get_b, self.set_b, None, "b is a property")

def get_a(self):
return self._a
def set_a(self, value):
self._a = value

def get_b(self):
return self._b
def set_b(self, value):
self._b = value


test = MyClass()
for k,v in test.__dict__.iteritems():
if isinstance(v, property):
print k, v.__doc__

 

[Marc 'BlackJack' Rintsch]

The only way I could get this to work was to change the way the
properties were defined/initalized:

That's because you iterate over the instance's `__dict__` and not over the
*class* `__dict__` like Neil does.

Ciao,
Marc 'BlackJack' Rintsch

 

[Gabriel Genellina]

En Mon, 25 Jun 2007 15:10:25 -0300, Marc 'BlackJack' Rintsch

That's because you iterate over the instance's `__dict__` and not over
the
*class* `__dict__` like Neil does.

I would iterate over dir(MyClass) instead - only because I prefer to hide
such implementation details.

 

[=?iso-8859-1?B?QW5kcuk=?=]

This is off the cuff. There's likely a better way.

for k, v in MyClass.__dict__.iteritems():
if isinstance(v, property):
print k, v.__doc__

Thank you, this solved my problem nicely.

André