Allow iterating over all events

ctapipe/io/simteleventsource.py

@@ -429,6 +429,14 @@ class SimTelEventSource(EventSource):
         config=True
     )
 
+    skip_non_triggered_events = Bool(
+        True,
+        help=(
+            "If False, also yield events where no telescope has triggered",
+            " meaning only shower information will be available.",
+        ),
+    ).tag(config=True)
+
     focal_length_choice = UseEnum(
         FocalLengthKind,
         default_value=FocalLengthKind.EFFECTIVE,
@@ -499,6 +507,7 @@ def __init__(self, input_url=Undefined, config=None, parent=None, **kwargs):
             self.input_url.expanduser(),
             allowed_telescopes=self.allowed_tels,
             skip_calibration=self.skip_calibration_events,
+            skip_non_triggered=self.skip_non_triggered_events,
         )
 
         self._subarray_info = self.prepare_subarray_info(
@@ -732,8 +741,9 @@ def _generate_events(self):
             data.meta["input_url"] = self.input_url
             data.meta["max_events"] = self.max_events
 
-            telescope_events = array_event["telescope_events"]
-            tracking_positions = array_event["tracking_positions"]
+            if trigger is None:
+                yield data
+                continue
 
             photoelectron_sums = array_event.get("photoelectron_sums")
             if photoelectron_sums is not None:
@@ -751,6 +761,9 @@ def _generate_events(self):
             else:
                 impact_distances = np.full(len(self.subarray), np.nan) * u.m
 
+            telescope_events = array_event["telescope_events"]
+            tracking_positions = array_event["tracking_positions"]
+
             for tel_id, telescope_event in telescope_events.items():
                 adc_samples = telescope_event.get("adc_samples")
                 if adc_samples is None:
@@ -891,7 +904,9 @@ def _fill_event_pointing(tracking_position):
         return TelescopePointingContainer(azimuth=azimuth, altitude=altitude)
 
     def _fill_trigger_info(self, array_event):
-        trigger = array_event["trigger_information"]
+        trigger = array_event.get("trigger_information")
+        if trigger is None:
+            return None
 
         if array_event["type"] == "data":
             event_type = EventType.SUBARRAY

ctapipe/io/tests/test_simteleventsource.py

@@ -592,3 +592,26 @@ def test_starting_grammage():
     with SimTelEventSource(path, focal_length_choice="EQUIVALENT") as source:
         e = next(iter(source))
         assert e.simulation.shower.starting_grammage == 580 * u.g / u.cm**2
+
+
+def test_all_events():
+    path = "dataset://gamma_prod5.simtel.zst"
+
+    with SimTelEventSource(path, skip_non_triggered_events=False) as source:
+        reuse = source.simulation_config[1].shower_reuse
+        n_showers = source.simulation_config[1].n_showers
+
+        shower = 0
+        event = 0
+        total = 0
+        for e in source:
+            if total % reuse == 0:
+                event = 0
+                shower += 1
+            else:
+                event += 1
+
+            assert e.index.event_id == shower * 100 + event
+            total += 1
+
+        assert total == n_showers * reuse