pd deprecation fixes in availability.py

rdtools/availability.py

@@ -273,11 +273,13 @@ def _calc_loss_subsystem(self, low_threshold, relative_sizes,
         system_delta = 1 - power_system / virtual_full_power
 
         subsystem_fraction = relative_sizes / relative_sizes.sum()
-        smallest_delta = power_subsystem.le(low_threshold) \
-                                        .replace(False, np.nan) \
-                                        .multiply(subsystem_fraction) \
-                                        .min(axis=1) \
-                                        .fillna(1)  # use safe value of 100%
+        smallest_delta = (
+            power_subsystem.le(low_threshold)
+            .replace(False, np.nan)
+            .multiply(subsystem_fraction)
+            .min(axis=1)
+        )  # use safe value of 100%
+        smallest_delta.loc[smallest_delta.isnull] = 1
         is_downtime = system_delta > (0.75 * smallest_delta)
         is_downtime[looks_online.all(axis=1)] = False
 
@@ -415,20 +417,17 @@ def _calc_loss_system(self):
         all_times = self.power_system.index
         masked = looks_offline[self.power_expected > 0].reindex(all_times)
         # Note: in Series, (nan | True) is False, but (True | nan) is True
-        full_outage = (
-            masked.ffill().fillna(False) | masked.bfill().fillna(False)
-        )
-
+        full_outage = masked.ffill() | masked.bfill()
         # Find expected production and associated uncertainty for each outage
         diff = full_outage.astype(int).diff()
         starts = all_times[diff == 1].tolist()
         ends = all_times[diff.shift(-1) == -1].tolist()
         steps = diff[~diff.isnull() & (diff != 0)]
         if not steps.empty:
-            if steps[0] == -1:
+            if steps.iloc[0] == -1:
                 # data starts in an outage
                 starts.insert(0, all_times[0])
-            if steps[-1] == 1:
+            if steps.iloc[-1] == 1:
                 # data ends in an outage
                 ends.append(all_times[-1])
 
@@ -497,7 +496,7 @@ def _calc_loss_system(self):
 
         # generate a best-guess timeseries loss for the full outages by
         # scaling the expected power signal to match the actual
-        lost_power_full = pd.Series(0, index=self.loss_subsystem.index)
+        lost_power_full = pd.Series(0, index=self.loss_subsystem.index, dtype=float)
         expected_power = self.power_expected
         corrected_cumulative_energy = self.energy_cumulative.copy()
         for i, row in self.outage_info.iterrows():