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__repr__ and __str__ 

These methods are assumed to return a string value that represents the object. The former is meant to be more strict and specific—ideally, you should be able to copy the outcome, run it as a code, and get an identical instance, like this:

class Animal:    def __init__(self, age, diet):        self.age = age        self.diet = diet        def __repr__(self):        return f"Animal(age={self.age}, diet='{self.diet}')"

This is what the representation of this class will look like:

>>> Animal(1, 'worms')Animal(age=1, diet='worms')

Indeed, if you copy that text and run it as a code, you'll get an identical copy. It should be noted, though, that far from all libraries follow that rule. 

The latter method, __str__, is meant to be more human-readable. If ...