refactor: add boilerplate using generation script

generate/__init__.py

@@ -0,0 +1 @@
+"""Package used for auto generating the boilerplate in the quantities."""

generate/generate_boilerplate.py

@@ -0,0 +1,105 @@
+from __future__ import annotations
+
+from pathlib import Path
+
+TARGET_FILE_PATH = Path(__file__).parent.parent / "quantio" / "quantities.py"
+
+
+def generate_boilerplate(quantities_with_fields: dict[str, dict[str, str]]) -> None:
+    """Generate the boilerplate parts of the quantity classes."""
+    with TARGET_FILE_PATH.open() as target_file:
+        target_content = target_file.readlines()
+
+    target_content_with_boilerplate = []
+    current_class: str | None = None
+
+    current_line_is_part_of_autogenerated_code = False
+    for line in target_content:
+        if line.startswith("class "):
+            current_class = line.split("(")[0][6:]
+
+        if "# --- This part is auto generated. Do not change manually. ---" in line:
+            current_line_is_part_of_autogenerated_code = True
+            target_content_with_boilerplate.append(line)
+            target_content_with_boilerplate.extend(
+                _generate_init(quantities_with_fields[current_class])
+            )
+            target_content_with_boilerplate.extend(
+                _generate_properties(current_class, quantities_with_fields[current_class])
+            )
+
+        if "# --- End of auto generated part. ---" in line:
+            current_line_is_part_of_autogenerated_code = False
+
+        if current_line_is_part_of_autogenerated_code:
+            continue
+
+        target_content_with_boilerplate.append(line)
+
+    for line_number, line in enumerate(target_content_with_boilerplate):
+        if not line.endswith("\n"):
+            target_content_with_boilerplate[line_number] += "\n"
+
+    with TARGET_FILE_PATH.open("w") as target_file:
+        target_file.writelines(target_content_with_boilerplate)
+
+
+def _generate_init(units: dict[str, str]) -> list[str]:
+    code = [" " * 4 + "def __init__(", " " * 8 + "self,"]
+
+    for unit in units:
+        code.append(" " * 8 + f"{unit}: float = 0.0,")
+
+    code.append(" " * 4 + ") -> None:")
+    code.append(" " * 8 + "self._base_value = 0.0")
+
+    for unit, factor in units.items():
+        code.append(" " * 8 + f"self._base_value += {unit} * {factor}")
+
+    return code
+
+
+def _generate_properties(current_class: str, units: dict[str, str]) -> list[str]:
+    code = []
+
+    for unit, factor in units.items():
+        code.append("")
+        code.append(" " * 4 + "@property")
+        code.append(" " * 4 + f"def {unit}(self) -> float:")
+        code.append(" " * 8 + f'"""The {current_class.lower()} in {unit.replace("_", " ")}."""')
+        code.append(" " * 8 + f"return self._base_value / {factor}")
+
+    return code
+
+
+if __name__ == "__main__":
+    quantities_with_fields = {
+        "Area": {
+            "square_miles": "1609.34**2",
+            "square_kilometers": "10 ** (3 * 2)",
+            "square_meters": "10**0",
+            "square_feet": "0.3048**2",
+            "square_inches": "0.0254**2",
+            "square_centimeters": "10 ** (-2 * 2)",
+            "square_millimeters": "10 ** (-3 * 2)",
+            "square_micrometers": "10 ** (-6 * 2)",
+        },
+        "Length": {
+            "miles": "1609.34",
+            "kilometers": "10**3",
+            "meters": "10**0",
+            "feet": "0.3048",
+            "inches": "0.0254",
+            "centimeters": "10**-2",
+            "millimeters": "10**-3",
+            "micrometers": "10**-6",
+        },
+        "Time": {
+            "hours": "60 * 60",
+            "minutes": "60",
+            "seconds": "1",
+            "milliseconds": "10**-3",
+        },
+    }
+
+    generate_boilerplate(quantities_with_fields)

generate/quantities.py

@@ -0,0 +1,27 @@
+from __future__ import annotations
+
+from ._quantity_base import _QuantityBase
+
+
+class Area(_QuantityBase):
+    """The two-dimensional extent of an object."""
+
+    # --- This part is auto generated. Do not change manually. ---
+
+    # --- End of auto generated part. ---
+
+
+class Length(_QuantityBase):
+    """The one-dimensional extent of an object or the distance between two points."""
+
+    # --- This part is auto generated. Do not change manually. ---
+
+    # --- End of auto generated part. ---
+
+
+class Time(_QuantityBase):
+    """The duration of an event."""
+
+    # --- This part is auto generated. Do not change manually. ---
+
+    # --- End of auto generated part. ---

pyproject.toml

@@ -20,7 +20,7 @@ pytest = "<9.0"
 line-length = 101
 
 [tool.ruff.lint]
-exclude = ["test/*"]
+exclude = ["test/*", "generate/*"]
 select = ["ALL"]
 ignore = [
     "COM812",  # conflicts with ruff formatter
@@ -36,6 +36,8 @@ ignore = [
 
     "PGH003",  # necessary for _QuantityBase.__eq__()
 
+    "PLR0913", # many arguments are necessary for the quantities to enable enough different units
+
     "RUF012",  # does not work with constants
 
     "TCH001",  # adds hard to understand compexity without providing a benefit for smaller projects

quantio/_quantity_base.py

@@ -1,6 +1,6 @@
 from __future__ import annotations
 
-from abc import ABC, abstractmethod
+from abc import ABC
 
 from .exceptions import CanNotAddTypesError, CanNotSubtractTypesError
 
@@ -11,40 +11,27 @@ class _QuantityBase(ABC):
     _base_value: float
     "The base unit of the quantity."
 
-    @property
-    @abstractmethod
-    def _UNIT_CONVERSION(self) -> dict[str, float]:
-        """Table used for recording the units with conversion values."""
-
-    def __init__(self, **kwargs: float) -> None:
-        """Construct this class with the used units."""
-        self._base_value = kwargs.get("_base_value", 0.0)
-
-        for unit_name, factor in self._UNIT_CONVERSION.items():
-            self._base_value += kwargs.get(unit_name, 0.0) * factor
-
-        for unit_name, factor in self._UNIT_CONVERSION.items():
-
-            def make_property(factor: float) -> property:
-                return property(lambda self: self._base_value / factor)
-
-            setattr(self.__class__, unit_name, make_property(factor))
-
     def __eq__(self, other: object) -> bool:
         """Assess if this object is the same as another."""
-        if type(self) is not type(other):
-            return False
+        if isinstance(other, type(self)):
+            return self._base_value == other._base_value
 
-        return self._base_value == other._base_value  # type: ignore
+        return False
 
     def __add__(self, other: _QuantityBase) -> _QuantityBase:
         """Add two quantities of the same type."""
         if type(self) is not type(other):
             raise CanNotAddTypesError(self.__class__.__name__, other.__class__.__name__)
-        return type(self)(_base_value=self._base_value + other._base_value)
+
+        result = type(self)()
+        result._base_value = self._base_value + other._base_value
+        return result
 
     def __sub__(self, other: _QuantityBase) -> _QuantityBase:
         """Subtract two quantities of the same type."""
         if type(self) is not type(other):
             raise CanNotSubtractTypesError(self.__class__.__name__, other.__class__.__name__)
-        return type(self)(_base_value=self._base_value - other._base_value)
+
+        result = type(self)()
+        result._base_value = self._base_value - other._base_value
+        return result