[issue20481] Clarify type coercion rules in statistics module

[Steven D'Aprano]

Steven D'Aprano added the comment:

Attached is a patch which:

- documents that mixed types are not currently supported;

- changes the behaviour of _sum to raise TypeError on mixed input 
  types (mixing int and <other> is allowed, but nothing else);

- updates the tests;

- adds some documentation changes for issue 20389.

----------
Added file: http://bugs.python.org/file33978/stats.patch

_______________________________________
Python tracker <report at bugs.python.org>
<http://bugs.python.org/issue20481>
_______________________________________