main.py

@@ -18,8 +18,8 @@ try:
                 subjects.append(subject.Subject(user_input[2], user_input[3], user_input[4]))
         elif user_input[0] == "output":
             subject_get = subject.get_subject(subjects, user_input[1])
-            user_IO.user_output(subject_get.)
+            user_IO.user_output(subject_get.return_average_subject)
     raise SystemError
 
 except Exception as e:
-    print('ERROR' + str(e))
+    print('ERROR' + str(e))

subject.py

@@ -37,3 +37,10 @@ class Grade:
         self.grade = grade
         self.name = name
         self.date = date
+
+
+def get_subject(liste, name):
+    for subject in liste:
+        if subject.name == name:
+            return subject
+    return None