Chromium also uses these languages to a lesser degree:
Python code should follow PEP-8, except:
CamelCase()method and function names instead of
(The rationale for these is mostly legacy: the code was originally written following Google's internal style guideline, the cost of updating all of the code to PEP-8 compliance was not small, and consistency was seen to be a greater virtue than compliance.)
Depot tools contains a local copy of pylint, appropriately configured.
Note that asserts are of limited use, and should not be used for validating input – throw an exception instead. Asserts can be used for validating program logic, especially use of interfaces or invariants (e.g., asserting that a function is only called with dictionaries that contain a certain key). See Using Assertions Effectively.
See also the Chromium OS Python Style Guidelines.
When working on Web-based UI features, consult the Web Development Style Guide for the Chromium conventions used in JS/CSS/HTML files.
Internal uses of web languages, notably “layout” tests, should preferably follow these style guides, but it is not enforced.