Fix ordinal() suffix for negative integers#321
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ordinal() selected the suffix using value % 10 and value % 100, but Python's modulo on negative numbers is non-negative (e.g. -1 % 10 == 9), so negative inputs got the wrong suffix: ordinal(-1) returned '-1th' instead of '-1st', ordinal(-21) returned '-21th' instead of '-21st', etc. The docstring states it works for any integer, so compute the suffix from abs(value). Add regression tests for negative ordinals.
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Bug
ordinal()returns the wrong suffix for negative integers:The docstring states the function "works for any integer," so negatives are in scope.
Root cause
The suffix is selected with
value % 10/value % 100. Python's modulo on negative numbers returns a non-negative result (-1 % 10 == 9), so negative values index into the wrong_ORDINAL_SUFFIXESslot (9→"th"). Some negatives (e.g.-11,-12) happen to land on"th"correctly by coincidence, but-1,-2,-3,-21,-101, etc. are wrong.Fix
Compute the suffix from
abs(value). The displayed number keeps its sign. One-line logic change.Tests
Added negative cases to the
test_ordinalparametrization (-1→-1st,-2→-2nd,-3→-3rd,-11→-11th,-21→-21st,-101→-101st,-111→-111th, etc.). Verified the new cases fail on the current code and pass with the fix; full suite (696 tests) passes.