[FEATURE] Fix PEP 8 style and add comments

[FEATURE] Fix PEP 8 style and add comments
[FEATURE] Fix style code by PEP 8

[FEATURE] Fix style code by PEP 8 but some line longer 79

[FEATURE] comments and style PEP 8 in market.py

[FEATURE] No comment every single pylint warning
[FEATURE] Add comments to market.py

[FEATURE] Add comments to market.py

[FEATURE] Add comments to market.py
[FEATURE] Add comments with doc strings to market.py
Merge pull request #615 from Ignat99/feature

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