qiskit/quantum_info/operators/base_operator.py
def power(self, n):
        """Return the compose of a operator with itself n times.

        Args:
            n (int): the number of times to compose with self (n>0).

        Returns:
            BaseOperator: the n-times composed operator.

        Raises:
            QiskitError: if the input and output dimensions of the operator
            are not equal, or the power is not a positive integer.
        """
        # NOTE: if a subclass can have negative or non-integer powers
        # this method should be overriden in that class.
        if not isinstance(n, (int, np.integer)) or n < 1:
            raise QiskitError("Can only power with positive integer powers.")
        if self._input_dim != self._output_dim:
            raise QiskitError("Can only power with input_dim = output_dim.")
        ret = self.copy()
        for _ in range(1, n):
            ret = ret.compose(self)
        return ret
def power(self, n):
        """Return the compose of a operator with itself n times.

        Args:
            n (int): the number of times to compose with self (n>0).

        Returns:
            BaseOperator: the n-times composed operator.

        Raises:
            QiskitError: if the input and output dimensions of the operator
            are not equal, or the power is not a positive integer.
        """
        # NOTE: if a subclass can have negative or non-integer powers
        # this method should be overriden in that class.
        if not isinstance(n, (int, np.integer)) or n < 1:
            raise QiskitError("Can only power with positive integer powers.")
        if self._input_dim != self._output_dim:
            raise QiskitError("Can only power with input_dim = output_dim.")
        ret = self.copy()
        for _ in range(1, n):
            ret = ret.compose(self)
        return ret
Return the compose of a operator with itself n times.

        Args:
            n (int): the number of times to compose with self (n>0).

        Returns:
            BaseOperator: the n-times composed operator.

        Raises:
            QiskitError: if the input and output dimensions of the operator
            are not equal, or the power is not a positive integer.