Coding style

For Markdown, use the Google style.

General style

• ALL_CAPS_GLOBALS at top
• function_name
• ClassName
• variable_name
• +2 space indent, a legacy from Google
• 2 empty lines between file level symbols
• 1 empty line between class members

Line breaks

Keep line width under 80 chars. Break a line on a first syntactic structure, prefer hanging indent of 4 spaces over vertical alignment. Prefer parentheses for line joining over \. For JSON-like nested dicts and lists it's acceptable to use 2 space indent.

Yes:

str = (
    'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nullam diam met, '
    'tristique ac placerat sit amet: %s, %s' % (a, b))

func_call(
    param1=...,
    param2=...,
    param3=...)

like_json = {
  'key': {
    'a': {
      'b': 123,
      'c': 123,
      'd': 123,
    },
  },
}

No:

str = \
    'Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nullam diam met, '

str = ('Lorem ipsum dolor sit amet, consectetur adipiscing elit. Nullam diam '
       'met, ....')

func_call(param1=...,
          param2=...,
          param3=...)

fun_call(param1=..., param2=...,
    param3=...)

Import statements

• import modules, not symbols.
• from X import Y statements, then import X statements within a single block

Separations:

<import block of stdlib>

<import block of import sys.path hack, e.g. test_env. Needed for now>

<import block of appengine lib>

<import block of appengine third_party lib, e.g. webapp2, or in third_party/>

<import block of components and other application external libs>

<import block of application libs>