Fix format_number producing bogus output for large integers#83
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When format_number() receives an integer >= 10**16, str(float(number))
produces scientific notation (e.g. '1e+16'). The subsequent .partition('.')
call then returns ('1e+16', '', '') since there is no decimal point, and
the comma-insertion loop operates on the '1e+...' text as if it were
plain digits, yielding garbage output like '1e,+16'.
Fix by short-circuiting the float conversion for plain int types (using
type(x) is int) and using str(number) directly instead. This preserves
the exact decimal representation and lets the existing comma-insertion
and sign logic work correctly.
Fixes a wrong-results bug where format_number(10**16) returned '1e,+16'
instead of '10,000,000,000,000,000'.
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format_number() returns corrupted output like
'1e,+16'for any integer>= 10**16. The root cause:str(float(n))produces scientific notationfor those values (e.g.
'1e+16'), then.partition('.')sees no decimalpoint and the comma-insertion loop consumes the scientific-notation text
as if it were plain digits.
Before this fix:
After this fix:
The same bug affects any integer in the
[10**16, 10**30)range wherestr(float(n))switches to scientific notation. Beyond that range theinteger literal itself would lose precision in the float conversion.
The fix avoids the unnecessary
float()round-trip for plainintvalues, preserving the exact decimal string and letting the existing
comma-insertion and sign logic work correctly.
This PR was written with assistance from an AI tool (Claude Code),
under my direction and review.
Closes #NEW (issue not yet filed)