Code style fixes.

ctapipe_io_magic/__init__.py

@@ -983,13 +983,11 @@ class MarsRun:
         stereo_ids = []
 
         n_m1_events = len(self.event_data['M1']['stereo_event_number'])
-        if n_m1_events == 0:
-            return stereo_ids
         n_m2_events = len(self.event_data['M2']['stereo_event_number'])
-        if n_m2_events == 0:
+        if (n_m1_events == 0) or (n_m2_events == 0):
             return stereo_ids
 
-        if self.is_mc == False:
+        if not self.is_mc:
             data_trigger_pattern = 128
 
             m2_data_condition = (self.event_data['M2']['trigger_pattern'] == data_trigger_pattern)
@@ -1040,7 +1038,7 @@ class MarsRun:
         n_m1_events = len(self.event_data['M1']['stereo_event_number'])
         n_m2_events = len(self.event_data['M2']['stereo_event_number'])
 
-        if self.is_mc == False:
+        if not self.is_mc:
             data_trigger_pattern = 128
     
             m1_data_condition = self.event_data['M1']['trigger_pattern'] == data_trigger_pattern