---
title: mappers (latest version)
description: API reference for qiskit_fermions.mappers in the latest version of qiskit-fermions
source: https://quantum.cloud.ibm.com/docs/en/api/qiskit-fermions/mappers
---

# Representation Mappers

This module provides a framework for implementing custom representation mapper routines.

> **Note**
>
> The functions listed below do not have a counterpart in the C API.

|                                                                                                                                                                                                                                     |                                                                                                                                                                                                                              |
| ----------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- | ---------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |
| [`map_fermion_action_generators`](/docs/api/qiskit-fermions/mappers-map-fermion-action-generators#qiskit_fermions.mappers.map_fermion_action_generators "qiskit_fermions.mappers.map_fermion_action_generators")(operator, ...)     | Map a [`FermionOperator`](/docs/api/qiskit-fermions/operators-fermion-operator#qiskit_fermions.operators.FermionOperator "qiskit_fermions.operators.FermionOperator") to another operator type.                              |
| [`map_majorana_action_generators`](/docs/api/qiskit-fermions/mappers-map-majorana-action-generators#qiskit_fermions.mappers.map_majorana_action_generators "qiskit_fermions.mappers.map_majorana_action_generators")(operator, ...) | Map a [`MajoranaOperator`](/docs/api/qiskit-fermions/operators-majorana-operator#qiskit_fermions.operators.MajoranaOperator "qiskit_fermions.operators.MajoranaOperator") to another operator type.                          |
| [`map_edge_vertex_generators`](/docs/api/qiskit-fermions/mappers-map-edge-vertex-generators#qiskit_fermions.mappers.map_edge_vertex_generators "qiskit_fermions.mappers.map_edge_vertex_generators")(operator, ...\[, ...])         | Map a [`EdgeVertexOperator`](/docs/api/qiskit-fermions/operators-edge-vertex-operator#qiskit_fermions.operators.EdgeVertexOperator "qiskit_fermions.operators.EdgeVertexOperator") to another operator type.                 |
| [`map_transfer_vertex_generators`](/docs/api/qiskit-fermions/mappers-map-transfer-vertex-generators#qiskit_fermions.mappers.map_transfer_vertex_generators "qiskit_fermions.mappers.map_transfer_vertex_generators")(operator, ...) | Map a [`TransferVertexOperator`](/docs/api/qiskit-fermions/operators-transfer-vertex-operator#qiskit_fermions.operators.TransferVertexOperator "qiskit_fermions.operators.TransferVertexOperator") to another operator type. |