[AVRO-2234] Use native MappingProxyType instead of hand-written ImmutableDict

• Type: Improvement
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.9.0
• Component/s: python
• Assignee: Michael A. Smith
• Reporter: Michael A. Smith
• Created: 02/Oct/18 02:42
• Updated: 07/Nov/18 21:48
• Resolved: 07/Nov/18 15:09

Description

Per the rejection notice in PEP-416, there is no native ImmutableDict in Python. However, there is a MappingProxyType that makes a proxy to the mapping of a dictionary, and is fully native. For most purposes, including avro's, it's a fully suitable replacement for a real ImmutableDict implementation (except for a minor detail about JSON encoding that is easier to solve and support than maintaining a complete implementation of ImmutableDict.)

I propose that we drop ImmutableDict and replace it with MappingProxyType.

Issue Links

• links to: GitHub Pull Request #337