better API and actually fix meter costs

pyproject.toml

@@ -1,6 +1,6 @@
 [tool.poetry]
 name = "ubc"
-version = "0.0.3"
+version = "0.0.4"
 description = "Utility Bill Calculator"
 authors = ["Thomas Tu <[email protected]>"]
 

ubc/calculator.py

@@ -1,5 +1,10 @@
-from ubc.rates.openei.api import RateSchedule
 from dataclasses import dataclass
+from pandas import Timedelta
+
+from ubc.rates.openei.api import RateSchedule
+
+
+DELTA_HOUR = Timedelta("1 hour")
 
 
 @dataclass
@@ -113,14 +118,15 @@ def calculate_meter_charges(self, load):
         cost = num_days*self.schedule.meter
         return cost.rename("cost")
 
-    def calculate_total(self, load_kw, interval=1):
+    def calculate_total(self, load_kw):
         """
         Args:
             load_kw (pd.Series): timestamp series of demand data.
-            interval (float): Fraction of an hour for timestamp.
         """
+
+        interval = load_kw.index.freq.delta / DELTA_HOUR
         energy_charges = self.calculate_energy_charges(load_kw*interval)["cost"].resample("M").sum()
         demand_charges = self.calculate_demand_charges(load_kw)["cost"].sum(axis=1)
         flatdemand_charges = self.calculate_flatdemand_charges(load_kw)["cost"]
-        meter_charges = self.calculate_meter_charges(load_kw)["cost"]
+        meter_charges = self.calculate_meter_charges(load_kw)
         return (meter_charges + energy_charges + demand_charges + flatdemand_charges).rename("total_cost")

ubc/rates/openei/__init__.py

@@ -0,0 +1,3 @@
+from .api import RateSchedule as OpenEI
+
+__all__ = ["OpenEI"]