The Python Apprentice

Instance methods

Let's make our class a little more interesting, by adding a so-called instance method which returns the flight number. Methods are just functions defined within the class block, and instance methods are functions which can be called on objects which are instances of our class, such as f. Instance methods must accept a reference to the instance on which the method was called as the first formal argument, and by convention this argument is always called self.

We have no way of configuring the flight number value yet, so we'll just return a constant string:

class Flight:    def number(self):        return "SN060"

And from a fresh REPL:

>>> from airtravel import Flight>>> f = Flight()>>> f.number()SN060

Notice that when we call the method, ...