---
title: EvolutionFactory (v0.46)
description: API reference for qiskit.opflow.evolutions.EvolutionFactory in qiskit v0.46
source: https://eu-de.quantum.cloud.ibm.com/docs/en/api/qiskit/0.46/qiskit.opflow.evolutions.EvolutionFactory
---

# EvolutionFactory

*class* `qiskit.opflow.evolutions.EvolutionFactory`

[GitHub](https://github.com/qiskit/qiskit/tree/stable/0.46/qiskit/opflow/evolutions/evolution_factory.py)

Bases: [`object`](https://docs.python.org/3/library/functions.html#object)

Deprecated: A factory class for convenient automatic selection of an Evolution algorithm based on the Operator to be converted.

## Methods

### build

*static* `build(operator=None)`

A factory method for convenient automatic selection of an Evolution algorithm based on the Operator to be converted.

> **Deprecated since version 0.24.0**
>
> The method `qiskit.opflow.evolutions.evolution_factory.EvolutionFactory.build()` is deprecated as of qiskit-terra 0.24.0. It will be removed in the Qiskit 1.0 release. For code migration guidelines, visit [https://qisk.it/opflow\_migration](https://qisk.it/opflow_migration).

**Parameters**

**operator** ([*OperatorBase*](/docs/api/qiskit/0.46/qiskit.opflow.OperatorBase "qiskit.opflow.operator_base.OperatorBase")) – the Operator being evolved

**Returns**

the `EvolutionBase` best suited to evolve operator.

**Return type**

[EvolutionBase](/docs/api/qiskit/0.46/qiskit.opflow.evolutions.EvolutionBase "qiskit.opflow.evolutions.EvolutionBase")

**Raises**

[**ValueError**](https://docs.python.org/3/library/exceptions.html#ValueError) – If operator is not of a composition for which we know the best Evolution method.