qiskit/quantum_info/operators/pauli.py
def from_label(cls, label):
        r"""Take pauli string to construct pauli.

        The qubit index of pauli label is q_{n-1} ... q_0.
        E.g., a pauli is $P_{n-1} \otimes ... \otimes P_0$

        Args:
            label (str): pauli label

        Returns:
            Pauli: the constructed pauli

        Raises:
            QiskitError: invalid character in the label
        """
        z = np.zeros(len(label), dtype=np.bool)
        x = np.zeros(len(label), dtype=np.bool)
        for i, char in enumerate(label):
            if char == 'X':
                x[-i - 1] = True
            elif char == 'Z':
                z[-i - 1] = True
            elif char == 'Y':
                z[-i - 1] = True
                x[-i - 1] = True
            elif char != 'I':
                raise QiskitError("Pauli string must be only consisted of 'I', 'X', "
                                  "'Y' or 'Z' but you have {}.".format(char))
        return cls(z=z, x=x)
def from_label(cls, label):
        r"""Take pauli string to construct pauli.

        The qubit index of pauli label is q_{n-1} ... q_0.
        E.g., a pauli is $P_{n-1} \otimes ... \otimes P_0$

        Args:
            label (str): pauli label

        Returns:
            Pauli: the constructed pauli

        Raises:
            QiskitError: invalid character in the label
        """
        z = np.zeros(len(label), dtype=np.bool)
        x = np.zeros(len(label), dtype=np.bool)
        for i, char in enumerate(label):
            if char == 'X':
                x[-i - 1] = True
            elif char == 'Z':
                z[-i - 1] = True
            elif char == 'Y':
                z[-i - 1] = True
                x[-i - 1] = True
            elif char != 'I':
                raise QiskitError("Pauli string must be only consisted of 'I', 'X', "
                                  "'Y' or 'Z' but you have {}.".format(char))
        return cls(z=z, x=x)
def from_label ( cls , label ) : z = np . zeros ( len ( label ) , dtype = np . bool ) x = np . zeros ( len ( label ) , dtype = np . bool ) for i , char in enumerate ( label ) : if char == 'X' : x [ - i - 1 ] = True elif char == 'Z' : z [ - i - 1 ] = True elif char == 'Y' : z [ - i - 1 ] = True x [ - i - 1 ] = True elif char != 'I' : raise QiskitError ( "Pauli string must be only consisted of 'I', 'X', " "'Y' or 'Z' but you have {}." . format ( char ) ) return cls ( z = z , x = x )
r"""Take pauli string to construct pauli.

        The qubit index of pauli label is q_{n-1} ... q_0.
        E.g., a pauli is $P_{n-1} \otimes ... \otimes P_0$

        Args:
            label (str): pauli label

        Returns:
            Pauli: the constructed pauli

        Raises:
            QiskitError: invalid character in the label
r Take pauli string to construct pauli .