Reduce the doctest lease duration...

[python_utils.git] / conversion_utils.py

diff --git a/conversion_utils.py b/conversion_utils.py
index 684edc0a9116aa827db2c7c83a52de10dbbba73b..57902a79754e2b7950f800cf82d3bdabc74114a9 100644 (file)
--- a/conversion_utils.py
+++ b/conversion_utils.py
@@ -1,7 +1,11 @@
 #!/usr/bin/env python3
+# -*- coding: utf-8 -*-
 
-from numbers import Number
-from typing import Callable
+# © Copyright 2021-2022, Scott Gasch
+
+"""Utilities involving converting between different units."""
+
+from typing import Callable, SupportsFloat
 
 import constants
 
@@ -30,22 +34,39 @@ class Converter(object):
         category: str,
         to_canonical: Callable,  # convert to canonical unit
         from_canonical: Callable,  # convert from canonical unit
-        unit: str,
+        suffix: str,
     ) -> None:
+        """Construct a converter.
+
+        Args:
+            name: the unit name
+            category: the converter category
+            to_canonical: a Callable to convert this unit into the
+                canonical unit of the category.
+            from_canonical: a Callable to convert from the canonical
+                unit of this category into this unit.
+            suffix: the abbreviation of the unit name.
+        """
+
         self.name = name
         self.category = category
         self.to_canonical_f = to_canonical
         self.from_canonical_f = from_canonical
-        self.unit = unit
+        self.suffix = suffix
 
-    def to_canonical(self, n: Number) -> Number:
+    def to_canonical(self, n: SupportsFloat) -> SupportsFloat:
+        """Convert into the canonical unit of this caregory by using the
+        Callable provided during construction."""
         return self.to_canonical_f(n)
 
-    def from_canonical(self, n: Number) -> Number:
+    def from_canonical(self, n: SupportsFloat) -> SupportsFloat:
+        """Convert from the canonical unit of this category by using the
+        Callable provided during construction."""
         return self.from_canonical_f(n)
 
     def unit_suffix(self) -> str:
-        return self.unit
+        """Get this unit's suffix abbreviation."""
+        return self.suffix
 
 
 # A catalog of converters.
@@ -97,7 +118,17 @@ conversion_catalog = {
 }
 
 
-def convert(magnitude: Number, from_thing: str, to_thing: str) -> float:
+def convert(magnitude: SupportsFloat, from_thing: str, to_thing: str) -> float:
+    """Convert between units using the internal catalog.
+
+    Args:
+        magnitude: the quantity from which to convert
+        from_thing: the quantity's source unit we're coverting from
+        to_thing: the unit we are coverting to
+
+    Returns:
+        The converted magnitude.  Raises on error.
+    """
     src = conversion_catalog.get(from_thing, None)
     dst = conversion_catalog.get(to_thing, None)
     if src is None or dst is None:
@@ -107,7 +138,8 @@ def convert(magnitude: Number, from_thing: str, to_thing: str) -> float:
     return _convert(magnitude, src, dst)
 
 
-def _convert(magnitude: Number, from_unit: Converter, to_unit: Converter) -> float:
+def _convert(magnitude: SupportsFloat, from_unit: Converter, to_unit: Converter) -> float:
+    """Internal conversion code."""
     canonical = from_unit.to_canonical(magnitude)
     converted = to_unit.from_canonical(canonical)
     return float(converted)