fix: don't add sign if the float is negative (#345)

Fix #341

Signed-off-by: Frost Ming <[email protected]>

Author: frostming

CHANGELOG.md

@@ -1,5 +1,11 @@
 # Change Log
 
+## [unreleased]
+
+### Fixed
+
+- Remove the extra minus sign added to the float value after calculation. ([#341](https://github.com/python-poetry/tomlkit/issues/341))
+
 ## [0.12.4] - 2024-02-27
 
 ### Fixed

tomlkit/items.py

@@ -714,9 +714,8 @@ def as_string(self) -> str:
     def _new(self, result):
         raw = str(result)
 
-        if self._sign:
-            sign = "+" if result >= 0 else "-"
-            raw = sign + raw
+        if self._sign and result >= 0:
+            raw = f"+{raw}"
 
         return Float(result, self._trivia, raw)