Deferred Error Handling in Python: Return instead of Raise

Summary

This article shows a different way of handling errors in Python — deferred error handling. If exceptions or errors were returned instead of raises, we don’t have to interrupt the program but still provide a solution for different scenarios.

Target Audience

Python beginners who are interested in deferred error handling and have to catch specific exceptions instead of throwing an error.

WARNING: This method is not recommended if you need to resolve errors as soon as possible. Please read the new post, Deferred Error Handling in Python: Logging Errors to File, for a cleaner way to defer error handling.

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Outline

1. How to raise an error?
2. How to return an error?
3. Why return errors instead of raise?
4. How to handle different error cases?

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1. How to raise an error?

def stepOne(name: str):
    if isinstance(name, str):
        print(f"Hello, my name is {name}.")
    else:
        raise TypeError(f"Expected a string, but got {type(name)}!")