UserWarning — Expert Playground

Default category for warnings issued by the user

Python Playground

# Exception groups (Python 3.11+)
import sys
print(f"Python {sys.version}")

# Exception hierarchy inspection
print(f"UserWarning MRO:")
for cls in UserWarning.__mro__:
    print(f"  {cls.__name__}")

# Exception attributes
try:
    import warnings; warnings.warn("user warning", UserWarning)
except UserWarning as e:
    print(f"\nException attributes:")
    print(f"  args: {e.args}")
    print(f"  __traceback__: {type(e.__traceback__)}")

    # Traceback manipulation
    import traceback
    tb_lines = traceback.format_exception(type(e), e, e.__traceback__)
    print(f"  Traceback lines: {len(tb_lines)}")

Output

Click "Run" to execute your code

Understanding the exception hierarchy and traceback system helps build robust error handling and debugging tools.

Challenge

Try modifying the code above to explore different behaviors. Can you extend the example to handle a new use case?

View all Expert examples for UserWarning