# Migration guide

This chapter describes how to migrate between the different PyTango API versions.

- Moving to v9.4
  - Dependencies and installation
  - Empty spectrum and image attributes
  - Changes to extract_as when reading spectrum and image attributes
  - Non-bound user functions for read/write/isallowed and commands
  - High-level API for dynamic attributes
  - High-level API support for DevEnum spectrum and image attributes
  - Optionally add Python attributes to DeviceProxy instances
  - New attribute decorators
  - Broken logging with “%”
- Moving to v9.5
  - Dependencies and installation
  - Removal of DevInt
  - Short-name access to TestContext devices