What is the difference between __repr__ and __str__?

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__repr__ and __str__

In Python, __repr__ and __str__ are both special methods used to define how an object is represented as a string, but they serve different purposes:

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✅ __repr__: Developer-Friendly Representation

• Goal: Provide an unambiguous string representation of the object.

• Should ideally return a string that could be used to recreate the object.

• Used by:

  • repr(obj)

  • Interactive console

  • Debugging and logging

Example:

python
class Book:
    def __init__(self, title):
        self.title = title

    def __repr__(self):
        return f"Book('{self.title}')"

---

✅ __str__: User-Friendly Representation

• Goal: Provide a readable or nicely formatted string for end users.

• Used by:

  • str(obj)

  • print(obj)

Example:

python
class Book:
    def __init__(self, title):
        self.title = title

    def __str__(self):
        return f"Book title: {self.title}"

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💡 If Only __repr__ is Defined?

If you only define __repr__, str(obj) and print(obj) will fall back to using __repr__.

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🧠 Summary:

Method	Purpose	Used By	Return Style
__repr__	Developer/debug output	repr(), console	Precise, evaluatable
__str__	User-facing output	str(), print()	Readable, informal

✅ Best practice: Always define __repr__. Define __str__ if you want user-friendly output.

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