code: def rep_expectation(expr, **options):
      """
      Returns an ``<x'|A|x>`` type representation for the given operator.
  
      Parameters
      ==========
  
      expr : Operator
          Operator to be represented in the specified basis
  
      Examples
      ========
  
      >>> from sympy.physics.quantum.cartesian import XOp, PxOp, PxKet
      >>> from sympy.physics.quantum.represent import rep_expectation
      >>> rep_expectation(XOp())
      x_1*DiracDelta(x_1 - x_2)
      >>> rep_expectation(XOp(), basis=PxOp())
      <px_2|*X*|px_1>
      >>> rep_expectation(XOp(), basis=PxKet())
      <px_2|*X*|px_1>
  
      """
  
      if "index" not in options:
          options["index"] = 1
  
      if not isinstance(expr, Operator):
          raise TypeError("The passed expression is not an operator")
  
      basis_state = get_basis(expr, **options)
  
      if basis_state is None or not isinstance(basis_state, StateBase):
          raise NotImplementedError(
              "Could not get basis kets for this operator"
          )
  
      basis_kets = enumerate_states(basis_state, options["index"], 2)
  
      bra = basis_kets[1].dual
      ket = basis_kets[0]
  
      return qapply(bra * expr * ket)
  
imports: from sympy.core.add import Add
  from sympy.core.expr import Expr
  from sympy.core.mul import Mul
  from sympy.core.numbers import I
  from sympy.core.power import Pow
  from sympy.integrals.integrals import integrate
  from sympy.physics.quantum.dagger import Dagger
  from sympy.physics.quantum.commutator import Commutator
  from sympy.physics.quantum.anticommutator import AntiCommutator
  from sympy.physics.quantum.innerproduct import InnerProduct
  from sympy.physics.quantum.qexpr import QExpr
  from sympy.physics.quantum.tensorproduct import TensorProduct
  from sympy.physics.quantum.matrixutils import flatten_scalar
  from sympy.physics.quantum.state import KetBase, BraBase, StateBase
  from sympy.physics.quantum.operator import Operator, OuterProduct
  from sympy.physics.quantum.qapply import qapply
  from sympy.physics.quantum.operatorset import operators_to_state, state_to_operators
label_desc: Use image node_id 4 for calling a global function with example usage: rep_expectation(expr) and returns: qapply