Conventions

In this book, you will find a number of text styles that distinguish between different kinds of information. Here are some examples of these styles and an explanation of their meaning.

Code words in text, database table names, folder names, filenames, file extensions, pathnames, dummy URLs, user input, and Twitter handles are shown as follows: "So, we can change an object's type by changing its __class__ attribute."

A block of code is set as follows:

def __init__(self, name):
        self.name = name
        self._observers = weakref.WeakSet()

    def register_observer(self, observer):
        """attach the observing object for this subject
        """
        self._observers.add(observer)
        print("observer {0} now listening on {1}".format(
            observer.name, self.name))

When we wish to draw your attention to a particular part of a code block, the relevant lines or items are set in bold:

        self.assertFalse(assign_if_free(mworker, {}))
    
    def test_worker_free(self,):
        mworker = create_autospec(IWorker)
        mworker.configure_mock(**{'is_busy.return_value':False})
        self.assertTrue(assign_if_free(mworker, {}))

New terms and important words are shown in bold. Words that you see on the screen, for example, in menus or dialog boxes, appear in the text like this: "Let's take an example of an object iC instance of the C class with the str and lst attributes."

Note

Warnings or important notes appear in a box like this.

Tip

Tips and tricks appear like this.