[issue2531] float compared to decimal is silently incorrect.

[Bert Hughes]

Bert Hughes <b.hughes at fmpco.com> added the comment:

Expressions like "Decimal('100.0') < .01" being silently wrong (True!) is *very* dangerous behavior, it should raise exception like any other Decimal-float operation, and hopefully will be back-ported to 2.7. 

Eg: 3rd party module kinterbasdb, which provides access to Firebird database, returns floats from firebird large-int types (eg NUMERIC 18,2) in versions of kinrebasdb 3.2 or less, but in versions 3.3+ kinterbasdb retrieves large-int as type Decimal. This means if python/kinterbasdb users upgrade kinterbasdb they must be aware of this python bug, because all existing code must be inspected for "(retrieved Decimal value) compare (float)" statements, which before upgrade were Ok (retrieved float value) compare (float)) statements.

I'm new to this tracker, I hope this simply is added as an additional comment & squawk of dismay to the "float compared to decimal is silently incorrec" issue.

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nosy: +bertchughes
versions: +Python 2.6 -Python 2.7

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