Dealing with the __str__ method in classes with lots of attributes

[Chris Angelico]

On Thu, May 10, 2012 at 11:33 PM, Andreas Tawn <andreas.tawn at ubisoft.com> wrote:
> Say I've got a class...
>
> class test(object):
>    def __init__(self):
>        self.foo = 1
>        self.bar = 2
>        self.baz = 3
>
> I can say...
>
> def __str__(self):
>   return "foo: {0}\nbar: {1}\nbaz: {2}".format(self.foo, self.bar, self.baz)

This might be of use:

return """foo: {foo}
bar: {bar}
baz: {baz}""".format(**self.__dict__)

You're repeating yourself a bit, but this allows the labels to differ
from the format tags. If you're certain that you don't need that
flexibility, you could generate the format string dynamically:

return "\n".join(x+": {"+x+"}" for x in
("foo","bar","baz")).format(**self.__dict__)

That scales more nicely as the number of elements desired increases
(while still being 100% explicit - the presence and order of elements
is governed by the tuple), but is a bit inflexible and complicated.
I'd be inclined toward the triple-quoted-string one.

Tim Toady.

ChrisA