[Python-Dev] Another case for frozendict

[Victor Stinner]

The PEP has been rejected, but the MappingProxyType is now public:

$ ./python
Python 3.5.0a0 (default:5af54ed3af02, Jul 12 2014, 03:13:04)
>>> d={1:2}
>>> import types
>>> d = types.MappingProxyType(d)
>>> d
mappingproxy({1: 2})
>>> d[1]
2
>>> d[1] = 3
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
TypeError: 'mappingproxy' object does not support item assignment

Victor