The following is a complete list of Python warnings that can be raised. While most of these are self-explanatory, I have added brief descriptions to them for sake of clarity; these are derived from the "Built-in Exceptions" module of the Python 2.5 documentation.
- Warning: Base class for warning categories.
- UserWarning: Base class for warnings generated by user code.
- DeprecationWarning: Base class for warnings about deprecated features.
- PendingDeprecationWarning: Base class for warnings about features which will be deprecated in the future.
- SyntaxWarning: Base class for warnings about dubious syntax
- RuntimeWarning: Base class for warnings about dubious runtime behavior.
- FutureWarning: Base class for warnings about constructs that will change semantically in the future.
- ImportWarning: Base class for warnings about probable mistakes in module imports. New in version 2.5.
- UnicodeWarning: Base class for warnings related to Unicode. New in version 2.5.