[issue31145] PriorityQueue.put() fails with TypeError if priority_number in tuples of (priority_number, data) are the same.

[Raymond Hettinger]

Raymond Hettinger added the comment:

We already have recommendations in the heapq documentation on how to do a work-around.   I'm looking at the more general problem of how can we make it easy once again to decorate a value with a sort value (not just for heaps but for anyplace where comparisons are made).

I would like our preferred answer to be something better than, "take all your existing functions that use comparisons and make new variants that compute and cache key functions".   Instead, I would rather, "keep your existing functions simple and just wrap your data in something that specifies comparison values that are computed just once". 

The old Schwartzian transform (decorate-compare-undecorate) had broad applicability but was effectively killed when a simple tuple no longer served for decoration.  

FWIW, the DataClass discussion has also ventured into this territory (the field definitions can specify whether or not a field is included in the rich comparison methods).

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Python tracker <report at bugs.python.org>
<https://bugs.python.org/issue31145>
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