Adding Equality between schemas

[tusharmakkar08]

Fixes #208

[tusharmakkar08]

@alecthomas : Since __repr__ was the combination of object and extras and schemas, __eq__ was giving wrong in cases Required etc were present. Hence I proceeded with making a __str__ for Schema. Now it'll satisfy cases mentioned by @AndreaCrotti .

[alecthomas]

Ok... I feel like this could use some tests though.

[tusharmakkar08]

Aren't doctests sufficient ?

[alecthomas]

I was thinking more tests for deeply nested schemas, using things like Any() etc.

[tusharmakkar08]

Hmm..
I have couple of concerns:

• For scenarios like this:

  schema = Schema(Any(None, int))
  schema1 = Schema(Any(int, None))

Do we need to have schema==schema1 as True? If yes, then the current logic won't work.

• I'll add more tests using Nested schemas and stuff. I will create a separate PR for the same, instead of reverting this PR. Is it fine?

Thanks

[alecthomas]

Yeah, I'm not sure about Any (and possibly others) which is kind of why I brought it up. It's probably fine as-is though, for 99% of cases.

[tusharmakkar08]

Cool 👍