Some more handy helper functions.

beer/extras.py

@@ -9,6 +9,7 @@ RECIPE_URL = 'https://api.brewfather.app/v2/recipes'
 BATCH_URL = 'https://api.brewfather.app/v2/batches'
 PULL_LIMIT = 50
 
+
 BREWFATHER_CONVERT_LOOKUP = {  # local_name: brewfather_name
     'all': {
         'name': 'name',
@@ -87,11 +88,76 @@ def get_batches(api_user, api_key, batch=''):
 
     return data
 
+
 def sg_plato(sg):
     """Convert specific gravtiy to °P."""
     sg = float(sg)
     return (-1*616.868) + (1111.14*sg) - (630.272*sg**2) + (135.997*sg**3)
 
+
 def plato_sg(plato):
     """Convert °P to specific gravtiy."""
     return 1 + (plato / (258.6 - (plato/258.2) * 227.1))
+
+
+def kg_extract(v, sg):
+    """Calculate kg of extract based on volume and SG."""
+    return float(v) * float(sg) * sg_plato(sg)/100
+
+
+def convert(value, start_unit, end_unit):
+    """Convert units."""
+
+    family_dict = unit_family(start_unit)
+
+    if family_dict:
+        start = [val for key, val in family_dict.items()
+                 if start_unit in key.split(',')][0]
+
+        end = [val for key, val in family_dict.items()
+               if end_unit in key.split(',')][0]
+
+        return float(value) * end / start
+
+
+def unit_family(unit_name):
+    """Find unit family base on unit name."""
+
+    unit_lookup = [
+        {'name': 'length',
+         'units': {
+            'm,meter,meters': 1.0,
+            'cm,centimeter,centimeters': 100,
+            'mm,millimeter,millimeters': 1000,
+            'in,inch,inches': 39.3701,
+            'yd,yard,yards': 1.09361,
+            'ft,foot,feet': 3.28084,
+            'mi,mile,miles': 0.000621371,
+            'km,killometer,killometers': .001,
+            }},
+        {'name': 'mass',
+         'units': {
+            'kg,kilogram,kilograms': 1.0,
+            'g,gram,grams': 1000,
+            'lb,pound,pounds': 2.20462,
+            'oz,ounce,ounces': 35.274,
+            'st,stone': 0.157473,
+            }},
+        {'name': 'volume',
+         'units': {
+            'l,liter,liters': 1.0,
+            'ml,milliliter,milliliters': 1000,
+            'floz,fluid ounce,fluid ounces': 33.814,
+            'cup,cups': 4.22675,
+            'qt,quart,quarts': 1.05669,
+            'gal,gallon,gallons': 0.264172,
+            'ft^3,cubic foot,cubic feet': 0.0353147,
+            'pt,pint,pints': 4.22675/2,
+            'tsp,teaspoon,teaspoons': 202.884,
+            'tbsp,tablespoon,tablespoons': 202.884/3,
+            }},
+    ]
+
+    for family in unit_lookup:
+        if [key for key in family['units'] if unit_name in key.split(',')]:
+            return family['units']