Except block
An except block is a Python try-statement clause that handles an exception matching a specified type.
Python How-To
An except clause is the handler block within a Python try...except statement that executes when a matching exception is raised in the protected try clause.
- How it is used
- Handles expected failures inside Python try...except statements so applications can avoid crashing.
- How deep it goes
- Explains control flow, narrow try scope, explicit exception types, multiple clauses, grouped exceptions, and failure-path returns.
- Examples
- Uses task-string parsing, integer conversion, invalid urgency input, ValueError handling, and separate or grouped exception clauses.
- What you can do after
- Apply it via Python syntax to catch named exceptions, report failures, return fallback values, and preserve successful execution.
The Quick Python Book, Fourth Edition
An except clause is a branch of a Python try statement that handles exceptions matching a specified exception type.
- How it is used
- Handles expected runtime failures without necessarily crashing the program.
- How deep it goes
- Explains syntax, binding, tuples, propagation, and inheritance-based ordering, while deferring broader exception design details.
- Examples
- Demonstrates file reading with IOError, a custom EmptyFileError, ordered handlers, and completion reporting.
- What you can do after
- Apply Python except clauses to classify, report, and handle selected runtime errors.
Read how The Quick Python Book, Fourth Edition explains except block →
Related concepts
- try-catch statementpart of · A try-catch statement is a control-flow construct that executes code under exception handling and transfers control to a matching handler when an exception is raised.
- exceptionuses · An exception is a runtime signal or object representing an abnormal condition that interrupts ordinary program flow and may be handled or propagated.
- ValueErroruses · ValueError is a built-in Python exception raised when an operation receives an argument of an appropriate type but an inappropriate value.
- blockkind of · A code block is a grouped region of code treated as a unit, with boundaries and scope or execution behavior determined by its language or context.
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