Python

The standard for Python style and layout is PEP 8: Style Guide for Python Code.

There's an online style checker: pep8online.com

Pylint is a static analyzer.

Prospector is a static analyzer that combines multiple python static analyzers including Pylint.

Sublime text has the SublimeLinter plugin which can lint to both PEP8 and PEP257 automatically and adds warning icons to the gutter