Make classes in SSPEvent more dict-like

So that they can be serialized to YAML more easily.

sourcespec/ssp_event.py

@@ -46,7 +46,34 @@ def _dyne_cm_to_N_m(value):
     return None if value is None else value * 1e-7
 
 
-class SSPCoordinate():
+class _SSPEventBaseClass():
+    """
+    SourceSpec event base class.
+    """
+    # make the class subscriptable
+    def __getitem__(self, key):
+        return getattr(self, key)
+
+    def keys(self):
+        """
+        Return the event attribute names as a list.
+        """
+        return self.__dict__.keys()
+
+    def values(self):
+        """
+        Return the event attributes as a list.
+        """
+        return self.__dict__.values()
+
+    def items(self):
+        """
+        Return the event attributes as a list of tuples.
+        """
+        return self.__dict__.items()
+
+
+class SSPCoordinate(_SSPEventBaseClass):
     """
     SourceSpec coordinate class.
 
@@ -63,18 +90,14 @@ def __init__(self, value=None, units=None, **kwargs):
         else:
             raise ValueError('coordinate units must be deg')
 
-    # make the class subscriptable
-    def __getitem__(self, key):
-        return getattr(self, key)
-
     def __str__(self):
         try:
             return f'{self.value_in_deg:.4f}°'
         except TypeError as e:
             raise TypeError('Incomplete coordinate data') from e
 
 
-class SSPDepth():
+class SSPDepth(_SSPEventBaseClass):
     """
     SourceSpec depth class.
     """
@@ -84,10 +107,6 @@ def __init__(self, value=None, units=None, **kwargs):
         self.value = _float(value)
         self.units = units
 
-    # make the class subscriptable
-    def __getitem__(self, key):
-        return getattr(self, key)
-
     def __str__(self):
         try:
             return f'{self.value:.1f} {self.units}'
@@ -117,7 +136,7 @@ def value_in_km(self):
         raise ValueError('depth units must be m or km')
 
 
-class SSPHypocenter():
+class SSPHypocenter(_SSPEventBaseClass):
     """
     SourceSpec hypocenter class.
     """
@@ -139,10 +158,6 @@ def __init__(self, longitude=None, latitude=None, depth=None,
         self.depth = SSPDepth(**depth)
         self.origin_time = _time(origin_time)
 
-    # make the class subscriptable
-    def __getitem__(self, key):
-        return getattr(self, key)
-
     def __str__(self):
         try:
             return (
@@ -155,7 +170,7 @@ def __str__(self):
             raise TypeError('Incomplete hypocenter data') from e
 
 
-class SSPMagnitude():
+class SSPMagnitude(_SSPEventBaseClass):
     """
     SourceSpec magnitude class.
     """
@@ -166,10 +181,6 @@ def __init__(self, value=None, mag_type=None, **kwargs):
         self.mag_type = mag_type
         self.computed = False
 
-    # make the class subscriptable
-    def __getitem__(self, key):
-        return getattr(self, key)
-
     def __str__(self):
         try:
             mag_type = self.mag_type or 'M'
@@ -198,7 +209,7 @@ def from_scalar_moment(self, scalar_moment):
         self.computed = True
 
 
-class SSPScalarMoment():
+class SSPScalarMoment(_SSPEventBaseClass):
     """
     SourceSpec scalar moment class.
     """
@@ -209,10 +220,6 @@ def __init__(self, value=None, units=None, **kwargs):
         self.units = units
         self.to_N_m()
 
-    # make the class subscriptable
-    def __getitem__(self, key):
-        return getattr(self, key)
-
     def __str__(self):
         try:
             return (
@@ -247,7 +254,7 @@ def from_moment_tensor(self, moment_tensor):
         self.to_N_m()
 
 
-class SSPFocalMechanism():
+class SSPFocalMechanism(_SSPEventBaseClass):
     """
     SourceSpec focal mechanism class.
 
@@ -261,10 +268,6 @@ def __init__(self, strike=None, dip=None, rake=None, units=None, **kwargs):
         self.rake = _float(rake)
         self.units = units  # currently not used
 
-    # make the class subscriptable
-    def __getitem__(self, key):
-        return getattr(self, key)
-
     def __str__(self):
         try:
             return (
@@ -290,7 +293,7 @@ def from_moment_tensor(self, moment_tensor):
         self.strike, self.dip, self.rake = _fps1
 
 
-class SSPMomentTensor():
+class SSPMomentTensor(_SSPEventBaseClass):
     """
     SourceSpec moment tensor class.
     """
@@ -307,10 +310,6 @@ def __init__(self, units=None, m_rr=None, m_tt=None, m_pp=None, m_rt=None,
         self.m_tp = _float(m_tp)
         self.to_N_m()
 
-    # make the class subscriptable
-    def __getitem__(self, key):
-        return getattr(self, key)
-
     def __str__(self):
         try:
             return (
@@ -338,7 +337,7 @@ def to_N_m(self):
             self.units = 'N-m'
 
 
-class SSPEvent():
+class SSPEvent(_SSPEventBaseClass):
     """
     SourceSpec event class.
     """
@@ -359,10 +358,6 @@ def __init__(self, event_dict=None):
         if event_dict is not None:
             self.from_event_dict(event_dict)
 
-    # make the class subscriptable
-    def __getitem__(self, key):
-        return getattr(self, key)
-
     def __str__(self):
         outstr = ''
         if self.event_id is not None: