Fix regression in reading event information from SAC header

sourcespec2/input/augment_traces.py

@@ -24,7 +24,7 @@
 from .sac_header import (
     compute_sensitivity_from_SAC,
     get_instrument_from_SAC, get_station_coordinates_from_SAC,
-    get_event_from_SAC, get_picks_from_SAC)
+    get_picks_from_SAC)
 logger = logging.getLogger(__name__.rsplit('.', maxsplit=1)[-1])
 
 
@@ -287,21 +287,15 @@ def _add_coords(trace):
 _add_coords.skipped = []  # noqa
 
 
-def _add_event(trace, ssp_event=None):
+def _add_event(trace, ssp_event):
     """
     Add ssp_event object to trace.
 
     :param trace: ObsPy Trace object
     :type trace: :class:`obspy.core.trace.Trace`
-    :param ssp_event: SSPEvent object (default: None)
+    :param ssp_event: SSPEvent object
     :type ssp_event: :class:`sourcespec.ssp_event.SSPEvent`
     """
-    if ssp_event is None:
-        # Try to get hypocenter information from the SAC header
-        try:
-            ssp_event = get_event_from_SAC(trace)
-        except Exception:
-            return
     trace.stats.event = ssp_event
 
 

sourcespec2/input/sac_header.py

@@ -126,10 +126,16 @@ def get_event_from_SAC(trace):
         raise RuntimeError(
             f'{trace.id}: not a SAC trace: cannot get hypocenter from header'
         ) from e
-    evla = sac_hdr['evla']
-    evlo = sac_hdr['evlo']
-    evdp = sac_hdr['evdp']
-    begin = sac_hdr['b']
+    try:
+        evla = sac_hdr['evla']
+        evlo = sac_hdr['evlo']
+        evdp = sac_hdr['evdp']
+        begin = sac_hdr['b']
+    except KeyError as e:
+        raise RuntimeError(
+            f'{trace.id}: cannot find hypocenter information in SAC header: '
+            f'{e}'
+        ) from e
     starttime = trace.stats.starttime
     try:
         tori = sac_hdr['o']

sourcespec2/input/traces.py

@@ -24,6 +24,7 @@
 from obspy import read
 from obspy.core import Stream
 from ..setup import config, ssp_exit
+from .sac_header import get_event_from_SAC
 logger = logging.getLogger(__name__.rsplit('.', maxsplit=1)[-1])
 
 
@@ -108,6 +109,23 @@ def _read_trace_files():
     return st
 
 
+def _read_event_from_traces(stream):
+    """
+    Read event information from trace headers.
+    The event information is stored in the trace.stats.event attribute.
+
+    Currently supports only the SAC header.
+
+    :param stream: ObsPy Stream object
+    :type stream: :class:`obspy.core.stream.Stream`
+    """
+    for trace in stream:
+        try:
+            trace.stats.event = get_event_from_SAC(trace)
+        except RuntimeError:
+            continue
+
+
 def read_traces():
     """
     Read trace files
@@ -116,10 +134,11 @@ def read_traces():
     :rtype: :class:`obspy.core.stream.Stream`
     """
     logger.info('Reading traces...')
-    st = _read_trace_files()
+    stream = _read_trace_files()
+    _read_event_from_traces(stream)
     logger.info('Reading traces: done')
     logger.info('---------------------------------------------------')
-    if len(st) == 0:
+    if len(stream) == 0:
         logger.error('No trace loaded')
         ssp_exit(1)
-    return st
+    return stream