Initial Import.

app/stores/utils.py

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+from math import radians, cos, sin, asin, sqrt
+from django.core.cache import cache
+from geopy.geocoders import GoogleV3
+
+
+def haversine(lon1, lat1, lon2, lat2):
+    """
+    Calculate the great circle distance between two points
+    on the earth (specified in decimal degrees)
+    """
+    # convert decimal degrees to radians
+    lon1, lat1, lon2, lat2 = map(radians, [lon1, lat1, lon2, lat2])
+    # haversine formula
+    dlon = lon2 - lon1
+    dlat = lat2 - lat1
+    a = sin(dlat/2)**2 + cos(lat1) * cos(lat2) * sin(dlon/2)**2
+    c = 2 * asin(sqrt(a))
+    km = 6367 * c
+    return km
+
+
+def caching_geo_lookup(address):
+    """
+    Preforms a geo lookup against Google V3 and caches the results
+    """
+    if not address:
+        return None
+    slug = address.lower().replace(',', '').replace(' ', '-')
+    geo = cache.get('geo_%s' % slug)
+    if not geo:
+        try:
+            geo = GoogleV3().geocode(address)
+        except ValueError:
+            return None
+        cache.set('geo_%s' % slug, geo, 3600)
+    return geo