RAVEN Software Coding Standard

RAVEN follows the Chromium coding standard for Python code (see https://www.chromium.org/chromium-os/python-style-guidelines). Among the several rules, RAVEN strictly enforces the following:

General coding standards

• Use 2 spaces for each indent level.
• Class names should start with a Capital letter.
• Other variables should be camelBack case. (The test system uses PEP 8 for variable naming.)
• Private variables start with two underscores: __
• Protected variables should start with one underscore: _
• Function definitions should have at least one line of white-space afterwards.
• except: with no exception must never be used
• In order to be compatible with Python 3.x releases, any Python 2.x code, must have:

from __future__ import division, print_function, absolute_import

before any code. (Importing unicode_literals is allowed as part of the import, but only should be used if it is useful.)

• The so-called "wild importing" approach is FORBIDDEN, i.e. :

from aModule import *

• Multiple statements on one line are not allowed. For example the following is forbidden:

if makeAnimal: self.raiseAMessage("we just increased the MOOSE herd population")

and should be changed to:

if makeAnimal: 
  self.raiseAMessage("we just increased the MOOSE herd population")

• Tuple unpacking and packing should only be used when needed. For example:

a, b = 0, 1

should be rewritten to be:

a = 0
b = 1

However, using it for function returns and swapping is allowed, since it saves temporary variables:

a, b = b, a

or:

a, b = funct()

are allowed.

• Lines longer than 120 characters must be split.