Python classes

Python is an Object-Oriented Programming (OOP) language. The way Python creates objects are with the class keyword. A Python object is most commonly a collection of functions (methods), variables, and attributes (properties). Once a class is defined, you can create instances of such a class. The class serves as the blueprint of the subsequent instances.

The topic of object-oriented programming is outside the scope of this chapter, so here is a simple example of a router object definition:

    >>> class router(object):
    ...   def __init__(self, name, interface_number,
     vendor):
    ...     self.name = name
    ...     self.interface_number = interface_number
    ...     self.vendor = vendor
    ...
    >>>

Once defined, you are able to create as many instances of that class as you'd like:

    >>> r1 = router("SFO1-R1", 64, "Cisco")
    >>> r1.name
    'SFO1-R1'
    >>> r1.interface_number
    64
    >>> r1.vendor
    'Cisco'
    >>>
    >>> r2 = router("LAX-R2", 32, "Juniper")
    >>> r2.name
    'LAX-R2'
    >>> r2.interface_number
    32
    >>> r2.vendor
    'Juniper'
    >>>

Of course, there is a lot more to Python objects and OOP. We will see more examples in the future chapters.