qml.exceptions

This module contains all the custom exceptions and warnings used in PennyLane.

Warning

Unless you are a PennyLane or plugin developer, you will likely not need to use these classes directly. They are raised by PennyLane functions when errors are encountered.

Contents

The exceptions and warnings are organized by their category of use.

General Execution Errors

CaptureError	Errors related to PennyLane's Program Capture execution pipeline.
DeviceError	Exception raised when it encounters an illegal operation in the quantum circuit.
QuantumFunctionError	Exception raised when an illegal operation is defined in a quantum function.
TransformError	Raised when there is an error with the transform logic.
ConditionalTransformError	Error for using qml.cond incorrectly
QueuingError	Exception that is raised when there is a queuing error
WireError	Exception raised by a Wire object when it is unable to process wires.
MeasurementShapeError	An error raised when an unsupported operation is attempted with a quantum tape.
AutoGraphError	Errors related to PennyLane's AutoGraph submodule.
CompileError	Error encountered in the compilation phase.
DecompositionError	Base class for decomposition errors.
InvalidCapabilitiesError	Exception raised from invalid TOML files.
NonDifferentiableError	Exception raised if attempting to differentiate non-trainable tensor using Autograd.

Operator Property Errors

OperatorPropertyUndefined	Generic exception to be used for undefined Operator properties or methods.
DecompositionUndefinedError	Raised when an Operator's representation as a decomposition is undefined.
TermsUndefinedError	Raised when an Operator's representation as a linear combination is undefined.
MatrixUndefinedError	Raised when an Operator's matrix representation is undefined.
SparseMatrixUndefinedError	Raised when an Operator's sparse matrix representation is undefined.
EigvalsUndefinedError	Raised when an Operator's eigenvalues are undefined.
DiagGatesUndefinedError	Raised when an Operator's diagonalizing gates are undefined.
AdjointUndefinedError	Raised when an Operator's adjoint version is undefined.
PowUndefinedError	Raised when an Operator's power is undefined.
GeneratorUndefinedError	Exception used to indicate that an operator does not have a generator
ParameterFrequenciesUndefinedError	Exception used to indicate that an operator does not have parameter_frequencies

User Warnings

PennyLaneDeprecationWarning	Warning raised when a PennyLane feature is being deprecated.
ExperimentalWarning	Warning raised to indicate experimental/non-stable feature or support.
AutoGraphWarning	Warnings related to PennyLane's AutoGraph submodule.

code/qml_exceptions

 

Download Python script

 

Download Notebook

 

View on GitHub