Remove Python specific types from YAML output (use safe_dump?)

[django@…]

dumps produced by yaml.dump are not very language neutral.
safe_dump=True as serialize parameter will call yaml.safe_dump which doesn't have this problem.

[django@…]

add safe_dump argument to yaml serializer

[Russell Keith-Magee]

Configurability is great, but is there any compelling reason that we shouldn't just change the implementation to use safe_dump all the time? I'm not a YAML expert, but looking at the PyYAML docs, it appears that the only place the difference would matter is when serializing 'arbitrary Python objects'. I don't think we need this capability, and if we are, we should be able to work around it without too much difficulty.

[django@…]

a unicode object for example is considered a 'arbitrary Python objects'. this creates such nice looking dumps like:

​https://db.leipzig.freifunk.net/dns/yaml/domain/list/

the !!python/unicode is not very portable. however, i asked the yaml programmer about this issue befor filling this bug
and he said suggested using safe_dump.
i'm not so sure about this, using dump has many advantages when it comes to terms of mapping verify presice things.
I'm thinking about writing a extended mapper that causes relations to be mapped like the model.
But for portability reasons this is not suggested, therefor I suggest this argument.

[Russell Keith-Magee]

Ok. I'm -1 to adding a safe_dump argument to the serializer. However, I agree that the output format is not pretty. I've changed the ticket title to reflect the underlying problem.

It looks as if the YAML output has changed significantly since the unicode branch was merged - this is the underlying problem that should be solved. The solution may be to switch to using safe_dump all the time - I'll leave that decision to whoever tackles this problem.

[Daniel Poelzleithner]

better patch. use safe_dump with tests

[Jacob]

(In [6891]) Fixed #5268: the YAML serializer now uses yaml.safe_dump() instead the plain yaml.dump(); this makes YAML dumps more portable, and also removes the crufty '!!python/unicode' business. Thanks, poelzi.