Initial revision

1 files changed, 74 insertions, 0 deletions

diff --git a/conversion_utils.py b/conversion_utils.py
new file mode 100644
index 0000000..bab27e1
--- /dev/null
+++ b/conversion_utils.py
@@ -0,0 +1,74 @@
+#!/usr/bin/env python3
+
+from numbers import Number
+from typing import Callable
+
+
+class Converter(object):
+    def __init__(self,
+                 name: str,
+                 category: str,
+                 to_canonical: Callable,
+                 from_canonical: Callable,
+                 unit: str) -> None:
+        self.name = name
+        self.category = category
+        self.to_canonical = to_canonical
+        self.from_canonical = from_canonical
+        self.unit = unit
+
+    def to_canonical(self, n: Number) -> Number:
+        return self.to_canonical(n)
+
+    def from_canonical(self, n: Number) -> Number:
+        return self.from_canonical(n)
+
+    def unit_suffix(self) -> str:
+        return self.unit
+
+
+conversion_catalog = {
+    "Fahrenheit": Converter("Fahrenheit",
+                            "temperature",
+                            lambda f: (f - 32.0) * 0.55555555,
+                            lambda c: c * 1.8 + 32.0,
+                            "°F"),
+    "Celsius": Converter("Celsius",
+                         "temperature",
+                         lambda c: c,
+                         lambda c: c,
+                         "°C"),
+    "Kelvin": Converter("Kelvin",
+                        "temperature",
+                        lambda k: k - 273.15,
+                        lambda c: c + 273.15,
+                        "°K"),
+}
+
+
+def convert(magnitude: Number,
+            from_thing: str,
+            to_thing: str) -> Number:
+    src = conversion_catalog.get(from_thing, None)
+    dst = conversion_catalog.get(to_thing, None)
+    if src is None or dst is None:
+        raise ValueError("No known conversion")
+    return _convert(magnitude, src, dst)
+
+
+def _convert(magnitude: Number,
+             from_unit: Converter,
+             to_unit: Converter) -> Number:
+    canonical = from_unit.to_canonical(magnitude)
+    converted = to_unit.from_canonical(canonical)
+    return converted
+
+
+def f_to_c(temp_f: float) -> float:
+    """Fahrenheit to Celsius."""
+    return convert(temp_f, "Fahrenheit", "Celsius")
+
+
+def c_to_f(temp_c: float) -> float:
+    """Celsius to Fahrenheit."""
+    return convert(temp_c, "Celsius", "Fahrenheit")