Add default value for Hazard type

Recover the default empty string value for `haz_type` argument of
Hazard initializer.

climada/hazard/base.py

@@ -159,10 +159,10 @@ class Hazard():
     scalar, string, list, 1dim np.array of size num_events."""
 
     def __init__(self,
-                 haz_type: str,
                  intensity: sparse.csr_matrix,
                  centroids: Centroids,
                  date: np.ndarray,
+                 haz_type: str = "",
                  units: str = "",
                  frequency: Optional[np.ndarray] = None,
                  frequency_unit: str = DEF_FREQ_UNIT,
@@ -182,14 +182,15 @@ def __init__(self,
 
         Parameters
         ----------
-        haz_type : str
-            String indicating the hazard type (e.g., ``TC`` for tropical cyclone)
         intensity : sparse.csr_matrix
             The intensity of the hazard for each event. Shape ``(n_event, n_centroids)``
         centroids : Centroids
             The centroids on which this hazard is defined.
         date : np.array of int
             The ordinal representation of the date of each event.
+        haz_type : str (optional)
+            String indicating the hazard type (e.g., ``TC`` for tropical cyclone). This
+            parameter is passed to the hazard ``Tag``.
         units : str (optional)
             The physical units of the intensity (used for plotting)
         frequency : np.array of float (optional)

climada/hazard/test/test_base.py

@@ -55,10 +55,10 @@ def dummy_hazard():
                                    [4.3, 2.1, 1.0], [5.3, 0.2, 0.0]])
     units = 'm/s'
 
-    return Hazard(haz_type,
-                  intensity,
+    return Hazard(intensity,
                   centroids,
                   date,
+                  haz_type,
                   units,
                   frequency,
                   frequency_unit,
@@ -86,10 +86,10 @@ def setUp(self):
         self.intensity = sparse.csr_matrix([[1, 2], [1, 2], [1, 2]])
         self.fraction = sparse.csr_matrix([[1, 2], [1, 2], [1, 2]])
 
-        self.hazard = Hazard(self.haz_type,
-                             self.intensity,
+        self.hazard = Hazard(self.intensity,
                              self.centroids,
                              self.date,
+                             self.haz_type,
                              event_id=self.event_id,
                              event_name=self.event_name,
                              frequency=self.frequency,
@@ -101,32 +101,32 @@ def good_hazard(self):
 
     def test_minimal_hazard(self):
         """Check if stating only the required parameters works"""
-        Hazard(self.haz_type,
-               self.intensity,
+        Hazard(self.intensity,
                self.centroids,
                self.date,
+               self.haz_type,
                fast=False)
 
     def test_fast_init_fail(self):
         """Check if fast init correctly disables internal check"""
         frequency = np.array([1, 2])
         # Not fast: Should raise exception
         with self.assertRaises(ValueError) as cm:
-            Hazard(self.haz_type,
-                            self.intensity,
-                            self.centroids,
-                            self.date,
-                            event_id=self.event_id,
-                            event_name=self.event_name,
-                            frequency=frequency,
-                            fraction=self.fraction)
+            Hazard(self.intensity,
+                   self.centroids,
+                   self.date,
+                   self.haz_type,
+                   event_id=self.event_id,
+                   event_name=self.event_name,
+                   frequency=frequency,
+                   fraction=self.fraction)
         self.assertIn("Invalid Hazard.frequency", str(cm.exception))
 
         # Fast: Skip check
-        Hazard(self.haz_type,
-               self.intensity,
+        Hazard(self.intensity,
                self.centroids,
                self.date,
+               self.haz_type,
                event_id=self.event_id,
                event_name=self.event_name,
                frequency=frequency,