Getting a dictionary from an object

[Steven D'Aprano]

On Sat, 23 Jul 2005 13:50:36 -0400, Mike Meyer wrote:

>> I don't think this is particularly useful behaviour. How do you use it?
> 
>     def __str__(self):
>         return self._format % self

That doesn't work. It calls self.__str__ recursively until Python halts
the process.

>>> class Thing(dict):
...     _format = "Thing %s is good."
...     def __str__(self):
...             return self._format % self
...
>>> X = Thing()
>>> X  # calls __repr__ so is safe
{}
>>> str(X)  # not safe
  File "<stdin>", line 4, in __str__
  File "<stdin>", line 4, in __str__
  ...
  File "<stdin>", line 4, in __str__
  File "<stdin>", line 4, in __str__
RuntimeError: maximum recursion depth exceeded


-- 
Steven.