[FEATURE] Fix style code by PEP 8 for market.py

http://legacy.python.org/dev/peps/pep-0008/#id12
http://legacy.python.org/dev/peps/pep-0008/#id14
I would argue doc strings are much larger in code than one line comments. I wouldn't worry about code size. It's negligible in terms of repo and when compiled it's not included.

I've not heard the only include why in comments. I was always taught that comments should clarify unclear code or express intent which may include what is happening. In particular much of the contributors here may not understand how pieces of DHT code do what they're supposed to do so it may be somewhat educational in the short term.

I'm not arguing that we have shitty comments but that we should be judicious about just ripping out comments.