I've been teaching myself Python using the Python Crash Course book, and now that I've reached the end of it I've been going through various tutorial websites to practice/supplement what I've learned. However, I've run into something strange.

As far as I can see, the Python Crash Course book does not mention __str__(). When I started looking at some class tutorials, as that's something I'm struggling with, I've run into examples where they use a method called __str__().

I'm shaky as to what it does, and I'm even more confused by the examples. I see one on https://www.w3schools.com/python/python_classes.asp which uses the following code:

class Person:
  def __init__(self, name, age):
    self.name = name
    self.age = age

  def __str__(self):
    return f"{self.name}({self.age})"

p1 = Person("John", 36)

print(p1)

When run, it returns John 36. Then there's another example where the __str__() method is not used, and it returns <__main__.Person object at 0x15039e602100>.

Okay, fine. So I need to use __str__() for this to work. But in the Python Crash Course, it shows an example with a similar class, and it does not use a __str__() method, and it works fine:

class Car:
    
    def __init__(self, make, model, year):
        self.make = make
        self.model = model 
        self. year = year
        
    def get_descriptive_name(self):
        long_name = f"{self.year} {self.make} {self.model}"
        return long_name.title()
    
my_new_car = Car("Audi", "a4", "2024")
print(my_new_car.get_descriptive_name())

This returns "2004 Audi A4". But it does not use a __str__() method. Why?