More quantitites and boilerplate generation

generate/__init__.py

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

generate/generate_boilerplate.py

@@ -0,0 +1,128 @@
+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}")
+
+    code.append("")
+    return code
+
+
+def _generate_properties(current_class: str, units: dict[str, str]) -> list[str]:
+    code = []
+
+    for unit, factor in units.items():
+        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}")
+        code.append("")
+
+    return code
+
+
+if __name__ == "__main__":
+    quantities_with_fields = {
+        "Acceleration": {
+            "meters_per_square_second": "1",
+            "g_force": "(1 / 9.8)",
+        },
+        "Angle": {
+            "degrees": "(3.141592653589793 / 180)",
+            "radians": "1",
+        },
+        "Area": {
+            "square_miles": "1609.34**2",
+            "square_kilometers": "10 ** (3 * 2)",
+            "square_meters": "1",
+            "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": "1",
+            "feet": "0.3048",
+            "inches": "0.0254",
+            "centimeters": "10**-2",
+            "millimeters": "10**-3",
+            "micrometers": "10**-6",
+        },
+        "Mass": {
+            "tonnes": "10**3",
+            "kilograms": "1",
+            "pounds": "(1 / 2.20462)",
+            "ounces": "(1 / 35.27396)",
+            "grams": "10**-3",
+            "milligrams": "10**-6",
+            "micrograms": "10**-9",
+        },
+        "Velocity": {
+            "meters_per_second": "1",
+            "kilometers_per_hour": "(1 / 3.6)",
+            "miles_per_hour": "(1 / 2.23694)",
+        },
+        "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
@@ -32,6 +32,14 @@ ignore = [
 
     "ISC001",  # conflicts with ruff formatter
 
+    "N802",    # interferes with setting constant abstract properties
+
+    "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
     "TCH002",  # same as TCH001
     "TCH003",  # same as TCH001

quantio/__init__.py

@@ -1,5 +1,6 @@
 """The main quantio package."""
 
-from .quantities import Length
+from .exceptions import CanNotAddTypesError, CanNotSubtractTypesError
+from .quantities import Length, Time
 
-__all__ = ["Length"]
+__all__ = ["Length", "Time", "CanNotAddTypesError", "CanNotSubtractTypesError"]

quantio/_quantity_base.py

@@ -0,0 +1,37 @@
+from __future__ import annotations
+
+from abc import ABC
+
+from .exceptions import CanNotAddTypesError, CanNotSubtractTypesError
+
+
+class _QuantityBase(ABC):
+    """Parent class to all quantities."""
+
+    _base_value: float
+    "The base unit of the quantity."
+
+    def __eq__(self, other: object) -> bool:
+        """Assess if this object is the same as another."""
+        if isinstance(other, type(self)):
+            return self._base_value == other._base_value
+
+        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__)
+
+        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__)
+
+        result = type(self)()
+        result._base_value = self._base_value - other._base_value
+        return result

quantio/exceptions.py

@@ -0,0 +1,12 @@
+class CanNotAddTypesError(TypeError):
+    """Raised when two uncompatible quantities are added to one another."""
+
+    def __init__(self, self_type_descriptor: str, other_type_descriptor: str) -> None:
+        super().__init__(f"Can not add {other_type_descriptor} to {self_type_descriptor}")
+
+
+class CanNotSubtractTypesError(TypeError):
+    """Raised when two uncompatible quantities are subtracted from one another."""
+
+    def __init__(self, self_type_descriptor: str, other_type_descriptor: str) -> None:
+        super().__init__(f"Can not subtract {other_type_descriptor} from {self_type_descriptor}")