keep zh_CN doc up-to-date
Fixed wrong named class
Fixed some pep8 warnings
Removed unused imports
Fixed syntax error.
Merge pull request #490 from wladston/master

Fixing a syntax error.
Merge pull request #488 from myzhan/master

Keep zh_CN doc update-to-date
Merge pull request #489 from fatiherikli/master

Some fixes on tests