aggr.py: remove staff from CX export data (Legi number 00-000-000), and...

aggr.py: remove staff from CX export data (Legi number 00-000-000), and afterwards assert unique Legi numbers

mossutils/aggr.py

@@ -47,7 +47,12 @@ def aggregate(
   course_csv = course_csv[relevant_course_columns]
   course_csv["TotalScore"] = course_csv["TotalScore"].round(0)
   course_csv.set_index("Legi", inplace=True)
-  ## TODO: Remove staff from course_csv
+  course_csv.drop("00-000-000", inplace=True) ## NOTE: We assume that this indicates staff
+
+  duplicated_indices: pd.Index = course_csv[course_csv.index.duplicated()].index
+  assert \
+    duplicated_indices.size == 0, \
+    "Unexpectedly found duplicated Legi numbers (other than '00-000-000') in course CSV: {}".format(duplicated_indices.values)
 
   ## TODO: Could integrate eDoz data "Leistungskontrollen" to get information whether
   ##       or not a student is a repeater