exceptions.py

@@ -0,0 +1,22 @@
+class NotANumberException(Exception):
+    pass
+
+
+class SubjectNotExistingException(Exception):
+    pass
+
+
+class CategoryNotExistingException(Exception):
+    pass
+
+
+class WrongCaseException(Exception):
+    pass
+
+
+def convertible(string):
+    try:
+        float(string)
+        return True
+    except ValueError:
+        raise NotANumberException

main.py

@@ -1,38 +1,54 @@
 import subject
 import user_IO
+import serializer
+import encryption
+import exceptions
+import os
 
 subjects = []
 try:
     while True:
-        user_input = user_IO.user_input()
-        input_or_output = user_input[0]
-        if input_or_output == "input":
-            _edit = user_input[1]
-            _subject = user_input[2]
-            if _edit == "grade":
-                _category = user_input[3]
-                _grade = user_input[4]
-                _grade_name = user_input[5]
-                subject_edit = subject.get_subject(subjects, _subject)
-                if subject_edit:
-                    subject_edit.add_grade(_category, subject.Grade(_grade, _grade_name))
-            elif _edit == "category":
-                _category = user_input[3]
-                _rating = user_input[4]
-                subject_edit = subject.get_subject(subjects, _subject)
-                if subject_edit:
-                    subject_edit.add_grade_category(_category, _rating)
-            elif _edit == "subject":
-                _main = user_input[3]
-                _oral = user_input[4]
-                subjects.append(subject.Subject(_subject, _main, _oral))
-        elif input_or_output == "output":
-            _subject = user_input[1]
-            subject_get = subject.get_subject(subjects, _subject)
-            user_IO.user_output(subject_get.name, subject_get.return_grade_categories(),
+        try:
+            user_input = user_IO.user_input()
+            input_or_output = user_input[0]
+            if input_or_output == "input":
+                _edit = user_input[1]
+                _subject = user_input[2]
+                if _edit == "grade":
+                    _category = user_input[3]
+                    _grade = user_input[4]
+                    _grade_name = user_input[5]
+                    subject_edit = subject.get_subject(subjects, _subject)
+                    if subject_edit:
+                        subject_edit.add_grade(_category, subject.Grade(_grade, _grade_name))
+                elif _edit == "category":
+                    _category = user_input[3]
+                    _rating = user_input[4]
+                    subject_edit = subject.get_subject(subjects, _subject)
+                    if subject_edit:
+                        subject_edit.add_grade_category(_category, _rating)
+                elif _edit == "subject":
+                    _main = user_input[3]
+                    _oral = user_input[4]
+                    subjects.append(subject.Subject(_subject, _main, _oral))
+                else:
+                    raise exceptions.WrongCaseException
+            elif input_or_output == "output":
+                _subject = user_input[1]
+                subject_get = subject.get_subject(subjects, _subject)
+                user_IO.user_output(subject_get.name, subject_get.return_grade_categories(),
                                 [subject_get.return_average_of_category(i) for i in subject_get.return_grade_categories()],
                                 subject_get.return_average_of_subject())
-    raise SystemError
+            elif input_or_output == "exit":
+                break
+            else:
+                raise exceptions.WrongCaseException
+
+        except (exceptions.NotANumberException, exceptions.CategoryNotExistingException,
+                exceptions.SubjectNotExistingException, exceptions.WrongCaseException) as e:
+            user_IO.exception_raised(e)
+
+    
 
 except Exception as e:
     print('ERROR' + str(e))

serializer.py

@@ -1,6 +1,24 @@
+import json
+import subject
+
+
+class TempSubject:
+    def __init__(self, string):
+        self.__dict__ = json.loads(string)
+
+
 def serialize(subject):
     string = subject.__dict__
     for category in string["grades"]:
         for counter, grade in enumerate(string["grades"][category][0]):
             string["grades"][category][0][counter] = grade.__dict__
     return str(string)
+
+
+def deserialize(string):
+    temp = TempSubject(string)
+    _subject = subject.Subject(temp.name, bool(temp.main_subject), bool(temp.oral_exam))
+    for category in temp.grades:
+        _subject.add_grade_category(category, temp.grades[category][1])
+    return _subject
+

subject.py

@@ -1,4 +1,5 @@
 from datetime import datetime as str_date
+from exceptions import SubjectNotExistingException, CategoryNotExistingException
 
 
 class Subject:
@@ -32,6 +33,11 @@ class Subject:
             grade_sum += self.return_average_of_category(i)*self.grades[i][1]
         return grade_sum / rating_sum
 
+    def category_existing(self, category):
+        if category in self.grades:
+            return True
+        raise CategoryNotExistingException
+
 
 class Grade:
     def __init__(self, grade, name, date=str(str_date.now())):
@@ -44,4 +50,4 @@ def get_subject(liste, name):
     for subject in liste:
         if subject.name == name:
             return subject
-    return None
+    raise SubjectNotExistingException

user_IO.py

@@ -1,5 +1,8 @@
+import exceptions
+
+
 def user_input():
-    todo = input("Ok, do you want to see them or to edit them [see/edit]?\n")
+    todo = input("Ok, do you want to see them or to edit them [see/edit/exit]?\n")
     if todo == "see":
         print("Which subject do you want to know the information?")
         subject = input()
@@ -14,23 +17,31 @@ def user_input():
                 main_subject = True
             elif main_subject == 'n':
                 main_subject = False
+            else:
+                raise exceptions.WrongCaseException
             oral_exam = input("Will there be an oral exam in this subject [y/n]? \n")
             if oral_exam == 'y':
                 oral_exam = True
             elif oral_exam == 'n':
                 oral_exam = False
+            else:
+                raise exceptions.WrongCaseException
             return "input", "subject", subject, main_subject, oral_exam
         elif user_add == "category":
             subject = input("To which subject do you want to add the category? \n")
             category = input("Which category do you want to add? \n")
             rating = float(input("Rating? \n"))
-            return "input", "category", subject, category, rating
+            if exceptions.convertible(rating):
+                return "input", "category", subject, category, rating
         elif user_add == "grade":
             subject = input("To which subject do you want to add the grade? \n")
             category = input("To which category do you want to add it? \n")
             grade = input("Grade? \n")
             grade_name = input("What's the name of the grade? \n")
-            return "input", "grade", subject, category, grade, grade_name
+            if exceptions.convertible(grade):
+                return "input", "grade", subject, category, grade, grade_name
+    elif todo == "exit":
+        return "exit"
 
 
 def user_output(subject, categories, average, average_subject):
@@ -41,4 +52,16 @@ def user_output(subject, categories, average, average_subject):
         for grade in categories[category][0]:
             string += str(grade.grade) + ", "
         print(string + "\n")
-    print("The average of {} is {}.".format(subject, average_subject))
+        print("The average of {} is {}.".format(subject, average_subject))
+
+
+def exception_raised(exception):
+    print("Dear user you've raised an exception. The cause of the exception is:")
+    if exception is exceptions.SubjectNotExistingException:
+        print("The subject you tried to access is not created")
+    elif exceptions is exceptions.CategoryNotExistingException:
+        print("The category you tried to add something is non-existent in this subject")
+    elif exception is exceptions.NotANumberException:
+        print("The number you gave the program is not a number")
+    elif exception is exceptions.WrongCaseException:
+        print("This was not one of the available choices")