self, string: str) -> str: code example

Example 1: <__main__.boat object at 0x7fc678e66cd0> even after using __str__

#!/bin/python3

import math
import os
import random
import re
import sys

class Car:
    def _init_(self,speed,unit):
        self.speed=speed
        self.unit=unit
    def __str__(self):
        return "Car with the maximum speed of {} {}".format(self.speed,self.unit)  

class Boat:
    def _init_(self,speed):
        self.speed=speed
    	def __str__(self):
        	return "Boat with the maximum speed of {} knots".format(self.speed)  
            
            
check the indentation of Boat class __str__() method, it should be as shown below.
  
class Boat:
    def _init_(self,speed):
        self.speed=speed
    def __str__(self):
        return "Boat with the maximum speed of {} knots".format(self.speed)

Example 2: string function in class python

class Person:
    name = ""
    age = 0

    def __init__(self, personName, personAge):
        self.name = personName
        self.age = personAge

    def __repr__(self):
        return {'name':self.name, 'age':self.age}

    def __str__(self):
        return 'Person(name='+self.name+', age='+str(self.age)+ ')'