PauliOperator

Initialize the Pauli operator from a term mapping.

Every term must act within 0..num_qubits-1. num_qubits=None defers the qubit count (useful while building a generator whose width is not yet known), but then get_majorana_operator and get_local_operator raise.

Number of terms in the operator.

Return a string representation of the operator.

Equal when num_qubits and term coefficients match exactly.

Check whether two PauliOperators have the same terms and close coefficients.

Coefficients are compared with numpy.isclose at rtol/atol; a differing qubit count is False, not an error.

Convert the Pauli operator to a MajoranaOperator via Jordan-Wigner.

Each local term is extended to the full num_qubits width (identities filled in) before the Jordan-Wigner map, so the resulting Majorana indices are global.

Pack the operator into the engine's native Pauli basis, as a MajoranaOperator.

Each term maps to its per-qubit gamma-slots -- X_q -> \{2q\}, Y_q -> \{2q+1\}, Z_q -> \{2q, 2q+1\} (see _pauli_to_local_slots) -- carrying its coefficient unchanged; a Hermitian Pauli operator's coefficients are real, but that is not checked here. The result is a MajoranaOperator only as a container for those slot tuples; it is not the Jordan-Wigner image (that is get_majorana_operator).

Whether every pair of Pauli terms in the operator commutes.

Returns True exactly when for every pair of Pauli terms $P_1, P_2$ are commuting. Equivalently, the number of qubits for which $P_1$ and $P_2$ have different non-identity letters is even.