Style Guidelines - PyGObject

Hide navigation sidebar
Hide table of contents sidebar
Back to top
Toggle table of contents sidebar

# Style Guidelines

## Python Code

- Generally follow Python’s PEP8 style guidelines. We run the pep8 command to verify this during unittest runs.

- Break up logical blocks of related code with a newline. Specifically add a blank newline after conditional or looping blocks.

- Don’t comment what is obvious. Instead prefer meaningful names of functions and variables:

      # Get the functions signal annotations <-- this comment is unnecessary
      return_type, arg_types = get_signal_annotations(func)

- Use comments to explain non-obvious blocks and conditionals, magic, workarounds (with bug references), or generally complex pieces of code. Good examples:

      # If a property was defined with a decorator, it may already have
      # a name; if it was defined with an assignment (prop = Property(...))
      # we set the property's name to the member name
      if not prop.name:
          prop.name = name

      # Python causes MRO's to be calculated starting with the lowest
      # base class and working towards the descendant, storing the result
      # in __mro__ at each point. Therefore at this point we know that
      # we already have our base class MRO's available to us, there is
      # no need for us to (re)calculate them.
      if hasattr(base, '__mro__'):
          bases_of_subclasses += [list(base.__mro__)]

## Python Doc Strings

- Doc strings should generally follow PEP257 unless noted here.

- Use reStructuredText (resST) annotations.

- Use three double quotes for doc strings (`"""`).

- Use a brief description on the same line as the triple quote.

- Include function parameter documentation (including types, returns, and raises) between the brief description and the full description. Use a newline with indentation for the parameters descriptions.

      def spam(amount):
          """Creates a Spam object with the given amount.

          :param int amount:
              The amount of spam.
          :returns:
              A new Spam instance with the given amount set.
          :rtype: Spam
          :raises ValueError:
              If amount is not a numeric type.

          More complete description.
          """

- For class documentation, use the classes doc string for an explanation of what the class is used for and how it works, including Python examples. Include `__init__` argument documentation after the brief description in the classes doc string. The class `__init__` should generally be the first method defined in a class putting it as close as possible (location wise) to the class documentation.

      class Bacon(CookedFood):
          """Bacon is a breakfast food.

          :param CookingType cooking_type:
              Enum for the type of cooking to use.
          :param float cooking_time:
              Amount of time used to cook the Bacon in minutes.

          Use Bacon in combination with other breakfast foods for
          a complete breakfast. For example, combine Bacon with
          other items in a list to make a breakfast:

          .. code-block:: python

              breakfast = [Bacon(), Spam(), Spam(), Eggs()]

          """
          def __init__(self, cooking_type=CookingType.BAKE, cooking_time=15.0):
              super(Bacon, self).__init__(cooking_type, cooking_time)