Initial commit

Added first version of JSONDecoder and pyproject.toml

---------

Co-authored-by: Fabian Kirchner <[email protected]>

Co-authored-by: Simon Stier <[email protected]>

pyproject.toml

@@ -0,0 +1,90 @@
+[build-system]
+requires = [
+    "setuptools>=61.0.0",
+    "setuptools-scm>=8.0",
+]
+build-backend = "setuptools.build_meta"
+
+[project]
+name = "ontopint"
+dynamic = ["version"]
+description = "A python package for reading units from a JSON-LD files and generating pint quantities."
+readme = "README.md"
+authors = [
+    { name = "Hampus Näsström", email = '[email protected]' },
+    { name = "Fabian Kirchner" },
+    { name = "Simon Stier" },
+]
+maintainers = [
+  { name = "Hampus Näsström", email = '[email protected]' }
+]
+classifiers = [
+    "Development Status :: 4 - Beta",
+    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3 :: Only",
+    "License :: OSI Approved :: MIT License",
+]
+dependencies = [
+    "rdflib",
+    "pint",
+]
+[project.optional-dependencies]
+dev = [
+    "pytest",
+]
+
+[project.license]
+file = "LICENSE"
+
+[project.urls]
+"Homepage" = "https://github.com/hampusnasstrom/ontopint"
+"Bug Tracker" = "https://github.com/hampusnasstrom/ontopint/issues"
+
+[tool.ruff]
+include = ["src/*.py", "tests/*.py"]
+select = [
+    "E", # pycodestyle
+    "W", # pycodestyle
+    "PL", # pylint
+]
+ignore = [
+    "E501", # Line too long ({width} > {limit} characters)
+    "E701", # Multiple statements on one line (colon)
+    "E731", # Do not assign a lambda expression, use a def
+    "E402",  # Module level import not at top of file
+    "PLR0911", # Too many return statements
+    "PLR0912", # Too many branches
+    "PLR0913", # Too many arguments in function definition
+    "PLR0915", # Too many statements
+    "PLR2004", # Magic value used instead of constant
+    "PLW0603", # Using the global statement
+    "PLW2901", # redefined-loop-name
+    "PLR1714", # consider-using-in
+    "PLR5501", # else-if-used
+]
+fixable = ["ALL"]
+exclude = ["dependencies"]
+
+# Same as Black.
+line-length = 88
+indent-width = 4
+
+[tool.ruff.format]
+# use single quotes for strings.
+quote-style = "single"
+
+# indent with spaces, rather than tabs.
+indent-style = "space"
+
+# Like Black, respect magic trailing commas.
+skip-magic-trailing-comma = false
+
+# Like Black, automatically detect the appropriate line ending.
+line-ending = "auto"
+
+[tool.setuptools.packages.find]
+where = [
+    "src",
+]
+
+[tool.setuptools_scm]

src/ontopint/__init__.py

@@ -0,0 +1,27 @@
+import json
+import rdflib
+from pint import UnitRegistry
+
+ureg = UnitRegistry()
+
+class UnitDecoder(json.JSONDecoder):
+    def __init__(self, *args, **kwargs):
+        json.JSONDecoder.__init__(self, object_hook=self.object_hook, *args, **kwargs)
+
+    def object_hook(self, obj):
+        if 'unit' in obj and 'value' in obj:
+            return ureg.Quantity(obj['value'], obj['unit'])
+        unit = None
+        unit_defs = [v for k, v in obj.items() if isinstance(v, str) and v.startswith('qudt:')]
+        if len(unit_defs) > 1:
+            raise ValueError('More that one unit definition')
+        if unit_defs:
+            iri = unit_defs[0].replace('qudt:', 'http://qudt.org/vocab/unit/')
+            graph = rdflib.Graph()
+            graph.parse(iri)
+            result = graph.query(f"SELECT * WHERE {{<{iri}> <http://qudt.org/schema/qudt/symbol> ?symbol}}")
+            unit = result.bindings[0]['symbol']
+            for k, v in obj.items():
+                if isinstance(v, float):
+                    obj[k] = ureg.Quantity(v, unit)
+        return obj