Truncate zeros for numeric values with negative exponent

CHANGELOG.md

@@ -11,6 +11,7 @@
 - Inline contexts that try to redefine @context now raise an error. Fixes [expand#ter56](https://w3c.github.io/json-ld-api/tests/expand-manifest.html#ter56) and [toRdf#ter56](https://w3c.github.io/json-ld-api/tests/toRdf-manifest.html#ter56).
 - When using native types, values of `xsd:boolean` and `xsd:integer` are now properly converted. Fixes [fromRdf#t0027](https://w3c.github.io/json-ld-api/tests/fromRdf-manifest.html#t0027).
 - Numbers with 0 as fractional part now parse to an `xsd:integer` instead of `xsd:double`. Fixes [toRdf#ttn02](https://w3c.github.io/json-ld-api/tests/toRdf-manifest.html#ttn02).
+- Zeros are now truncated for numeric values with negative exponent.
 
 ## 3.1.0 - 2026-06-19
 

lib/pyld/jsonld.py

@@ -6388,7 +6388,7 @@ def _is_double(v):
 
 def _canonicalize_double(value: float) -> str:
     """Convert a float value to canonical lexical form of `xsd:double`."""
-    return re.sub(r'(\d)0*E\+?0*(\d)', r'\1E\2', (f'{value:1.15E}'))
+    return re.sub(r'(\d)0*E\+?(-)?0*(\d)', r'\1E\2\3', (f'{value:1.15E}'))
 
 
 def _is_numeric(v):

tests/test_jsonld.py

@@ -1053,6 +1053,18 @@ def test_fractional(self):
         nquads = jsonld.to_rdf(input, options={'format': 'application/n-quads'})
         assert nquads == expected
 
+    # Issue 175
+    def test_truncate_zeros_with_negative_exponent_numbers(self):
+        """
+        Numeric values with negative exponent should truncate zeros
+        """
+        input = { "ex:value": 0.97 }
+
+        expected = '_:b0 <ex:value> "9.7E-1"^^<http://www.w3.org/2001/XMLSchema#double> .\n'
+
+        nquads = jsonld.to_rdf(input, options={'format': 'application/n-quads'})
+        assert nquads == expected
+
 class TestFromRDF:
     def test_compound_literal_direction_without_language(self):
         """