This program needs to implement the following functions:

1) Add Student: This operation adds a new student entry to the 'students.txt' file. The process begins by prompting the user for the student's first name and last name. The system needs to check that the name contains only letters, and the names start with capital letters. Subsequently, the system automatically generates the email address in the format of firstname.lastname@lut.fi. Additionally, the system generates a unique study number by randomly selecting a number between 10000 and 99999, ensuring it's not already in use. The starting year is automatically set to the current year, utilizing the 'datetime' library to retrieve this information."

2) Search student: You can find any student by giving a part of the first name or a part of the last name of a student. The search string must contain at least three non-blank characters. This operation is suitable for finding the students ID, which is needed in operations 4 and 5. The operation prints the ID, the first and the last name according to the example below.

3) Search course: You can give a part of the course name or part of the teacher's name. Note that there can be several teachers in one course.

4) Add course completion: The system asks the required information step by step according to the following examples. If student has already passed the course, the system checks that the new grade is higher than the old grade. There can be at most one completion of one course by one student. The system needs to also check that the completion is added to the register within 30 days. It this is not true, then the program outputs: Input date is older than 30 days. Please contact "opinto." In such a case, nothing is added to the file.

5) Show student’s record: The program asks the students ID. Remember that you can search the ID by using operation 2. After this, the program displays the student’s information according to the model below:

Result：

Code：

import random
import datetime

def menu():
    while 1:
        print('''You may select one of the following:
        1) Add student 
        2) Search student
        3) Search course
        4) Add course completion
        5) Show student's record
        0) Exit''')
        selection=input("What is your selection?\n")
        if selection=="1":
            Add_student()
            print()
            continue
        elif selection=="2":
            Search_student()
            print()
            continue
        elif selection=="3":
            Search_course()
            print()
            continue
        elif selection=="4":
            Add_course_com()
            print()
            continue
        elif selection=="5":
            Show_student_re()
            print()            
            continue
        elif selection=="0":
            break
        else:
            print("Try again,enter number 0--5 please.")
            print()
            continue



def Add_student():
    while True:
        print("Names should contain only letters and start with a capital letter.")
        First_name = input("Enter the first name of the student:\n")
        Last_name = input("Enter the last name of the student:\n")
        condition_firstname = 0
        condition_lastname = 0

        # Determine whether the condition for capitalizing the first letter of firstname is met
        if First_name[0].isupper():
            # Check if all characters in the rest of the firstname are lowercase letters
            if First_name[1:].islower() and First_name[1:].isalpha():
                condition_firstname = 1

        # Determine whether the condition for capitalizing the first letter of lastname is met
        if Last_name[0].isupper():
            # Check if all characters in the rest of the lastname are lowercase letters
            if Last_name[1:].islower() and Last_name[1:].isalpha():
                condition_lastname = 1

        # Meet all conditions
        if condition_firstname == 1 and condition_lastname == 1:
            break
        else:
            continue
    #Creat email
    email=First_name.lower()+"."+Last_name.lower()+"@lut.fi"

    #Selcet major
    while 1:
        print('''Select student's major:
            CE: Computational Engineering
            EE: Electrical Engineering 
            ET: Energy Technology
            ME: Mechanical Engineering
            SE: Software Engineering''')
        major=input("What is your selection?\n")
        if major=="CE" or major=="EE" or major=="ET" or major=="ME" or major=="SE":
            print("Student added successfully!")
            break
        else:
            continue


    #Retrieve existing student ID and generate new unique student ID
    list_ID = []
    with open("students.txt", "r") as fp:
        num_lines = len(fp.readlines())
        fp.seek(0)  #Reposition the file pointer to the beginning of the file
        for i in range(num_lines):
            ID = fp.readline().strip().split(",")[0]
            list_ID.append(ID)

    while 1:
        new_ID = random.randint(10000, 99999)
        if new_ID in list_ID:
            continue
        else:
            break
        
    #Get the current year
    current_datetime = datetime.datetime.now()
    current_year = current_datetime.year

    #Add information of new studnets
    with open("students.txt","a") as fp:
        content=str(new_ID)+","+First_name+","+Last_name+","+str(current_year)+","+major+","+email+"\n"
        fp.write(content)


        
def Search_student():
    while 1 :
        character=input("Give at least 3 characters of the students first or last name:\n")
        list_firstname=[]
        list_lastname=[]
        list_ID=[]
        if character[:].isalpha() and len(character)>=3:
            with open("students.txt","r") as fp:
                content=fp.readlines()
                num_lines = len(content)
                fp.seek(0)  #Reposition the file pointer to the beginning of the file
                for i in range(num_lines):
                    ID = fp.readline().strip().split(",")[0]
                    list_ID.append(ID)

                fp.seek(0)
                for i in range(num_lines):
                    firstname = fp.readline().strip().split(",")[1]
                    list_firstname.append(firstname)
                    
                fp.seek(0)
                for i in range(num_lines):
                    lastname = fp.readline().strip().split(",")[2]
                    list_lastname.append(lastname)
            
            n=[]
            for i in range(len(list_firstname)):
                if character in list_firstname[i]:
                    n.append(i)

            k=[]
            for i in range(len(list_lastname)):
                if character in list_lastname[i]:
                    k.append(i)

            #The input character cannot be detected
            if n==[] and k==[]:
                print("The student cannot be detected,Try again.\n")
                continue
            
            elif n!=[] and k==[]:
                print("Matching studnets:")
                for j in n:
                    if 0<=j < num_lines:
                        line_need=content[j].split(",")
                        print("ID: ",line_need[0],", First name: ",line_need[1],", Last name: ",line_need[2],sep="")
                break

            elif n==[] and k!=[]:
                print("Matching studnets:")
                for j in k:
                    if 0<=j < num_lines:
                        line_need=content[j].split(",")
                        print("ID: ",line_need[0],", First name: ",line_need[1],", Last name: ",line_need[2],sep="")
                break
            
            elif n!=[] and k!=[]:
                print("Matching studnets:")
                for j in n:
                    if 0<=j < num_lines:
                        line_need=content[j].split(",")
                        print("ID: ",line_need[0],", First name: ",line_need[1],", Last name: ",line_need[2],sep="")
                for j in k:
                    if 0<=j < num_lines:
                        line_need=content[j].split(",")
                        print("ID: ",line_need[0],", First name: ",line_need[1],", Last name: ",line_need[2],sep="")
                break

        else:
            continue
    return list_ID



def Search_course():
    while 1 :
        character=input("Give at least 3 characters of the name of the course or the teacher:\n")
        list_courses=[]
        list_teachers=[]
        list_ID=[]
        if character[:].isalpha() and len(character)>=3:
            with open("courses.txt","r") as fp:
                content=fp.readlines()
                num_lines = len(content)
            
                fp.seek(0)  #Reposition the file pointer to the beginning of the file
                for i in range(num_lines):
                    ID = fp.readline().strip().split(",")[0]
                    list_ID.append(ID)

                fp.seek(0)
                for i in range(num_lines):
                    courses_name = fp.readline().strip().split(",")[1]
                    list_courses.append(courses_name)
                    
                fp.seek(0)
                for i in range(num_lines):
                    teachers_name = fp.readline().strip().split(",",4)[3]
                    list_teachers.append(teachers_name)
            
            n=[]
            for i in range(len(list_courses)):
                if character in list_courses[i]:
                    n.append(i)

            k=[]
            for i in range(len(list_teachers)):
                if character in list_teachers[i]:
                    k.append(i)

            #The input character cannot be detected
            if n==[] and k==[]:
                print("The course cannot be detected,Try again.\n")
                continue
            
            if n!=[] and k==[]:
                for j in n:
                    if 0<=j < num_lines:
                        line_need=content[j].split(",")
                        data_teachers=line_need[3:]
                        teachers=', '.join(element.strip() for element in data_teachers)
                        print("ID: ",line_need[0],", Name: ",line_need[1],", Teacher(s): ",teachers,sep="")
                break

            if n==[] and k!=[]:
                for j in k:
                    if 0<=j < num_lines:
                        line_need=content[j].split(",")
                        data_teachers=line_need[3:]
                        teachers=', '.join(element.strip() for element in data_teachers)
                        print("ID: ",line_need[0],", Name: ",line_need[1],", Teacher(s): ",teachers,sep="")
                break
            
            if n!=[] and k!=[]:
                for j in n:
                    if 0<=j < num_lines:
                        line_need=content[j].split(",")
                        data_teachers=line_need[3:]
                        teachers=', '.join(element.strip() for element in data_teachers)
                        print("ID: ",line_need[0],", Name: ",line_need[1],", Teacher(s): ",teachers,sep="")
                for j in k:
                    if 0<=j < num_lines:
                        line_need=content[j].split(",")
                        data_teachers=line_need[3:]
                        teachers=', '.join(element.strip() for element in data_teachers)
                        print("ID: ",line_need[0],", Name: ",line_need[1],", Teacher(s): ",teachers,sep="")
                break

        else:
            continue



def Add_course_com():
    list_courses_ID=[]
    list_date=[]
    list_student_ID=[]
    list_passed_grade=[]

    with open("passed.txt","r") as fp:
        content=fp.readlines()
        num_lines = len(content)
        
        fp.seek(0)  #Reposition the file pointer to the beginning of the file
        for i in range(num_lines):
            courses_ID = fp.readline().strip().split(",")[0]
            list_courses_ID.append(courses_ID)

        fp.seek(0)
        for i in range(num_lines):
            student_ID = fp.readline().strip().split(",")[1]
            list_student_ID.append(student_ID)
                
        fp.seek(0)
        for i in range(num_lines):
            passed_date = fp.readline().strip().split(",")[2]
            list_date.append(passed_date)

        fp.seek(0)
        for i in range(num_lines):
            passed_grade = fp.readline().strip().split(",")[3]
            list_passed_grade.append(passed_grade)
    
    check_courses_ID=input("Give the course ID:\n")
    while check_courses_ID not in list_courses_ID: 
        check_courses_ID=input("Give the course ID:\n")

    check_student_ID=input("Give the student ID:\n")
    while check_student_ID not in list_student_ID: 
        check_student_ID=input("Give the student ID:\n")
    
    grade=input("Give the grade:\n")
    if grade=="1"or grade=="2" or grade=="3"or grade=="4" or grade=="5":
        n=[]
        for i in range(len(list_courses_ID)):
            if check_courses_ID == list_courses_ID[i]:
                n.append(i)
        k=[]
        for j in range(len(list_student_ID)):
            if check_student_ID == list_student_ID[j]:
                k.append(j)

        need_lines_th=[]
        for a in n:
            for b in k:
                if a==b:
                    need_lines_th.append(a)
                    
        if need_lines_th==[]:
            try:
                t = input("Enter a date (DD/MM/YYYY):\n")
                new_date = datetime.datetime.strptime(t, "%d/%m/%Y")
                current_time = datetime.datetime.now()
                        
                if (current_time-new_date).days>30:
                    print("Input date is older than 30 days. Contact \"opinto\".")

                elif 30>=(current_time-new_date).days>=0:
                    with open("passed.txt","a") as fp:
                        content=check_courses_ID+","+check_student_ID+","+t+","+grade+"\n"
                        fp.write(content)
                    print("Input date is valid.")
                    print("Record added!")

                else:
                    print("Input date is later than today. Try again!")    

            except ValueError:
                print("Invalid date format. Use DD/MM/YYYY. Try again!")

        
        
        
        else:
            for num in need_lines_th:
                if list_passed_grade [num]>= grade:
                    print("Student has passed this course earlier with grade",list_passed_grade [num])
                else:
                    
                    try:
                        t = input("Enter a date (DD/MM/YYYY):\n")
                        new_date = datetime.datetime.strptime(t, "%d/%m/%Y")
                        current_time = datetime.datetime.now()
                        
                        if (current_time-new_date).days>30:
                            print("Input date is older than 30 days. Contact \"opinto\".")

                        elif 30>=(current_time-new_date).days>=0:
                            del content[need_lines_th[0]]
                            with open("passed.txt", 'w') as file:
                                file.writelines(content)
                            with open("passed.txt","a") as fp:
                                content=check_courses_ID+","+check_student_ID+","+t+","+grade+"\n"
                                fp.write(content)
                            print("Input date is valid.")
                            print("Record added!")
                            break

                        else:
                            print("Input date is later than today. Try again!")    

                    except ValueError:
                        print("Invalid date format. Use DD/MM/YYYY. Try again!")

    else:
        print("Grade is not a correct grade.")



def Show_student_re():
    need_lines_s=[]
    need_lines_p=[]
    need_lines_c=[]
    list_ID_s=[]
    list_ID_p=[]
    list_ID_c=[]
    with open("students.txt","r") as fp:
        content_s=fp.readlines()
        num_lines_s = len(content_s)
        fp.seek(0)  #Reposition the file pointer to the beginning of the file
        for i in range(num_lines_s):
            ID_s = fp.readline().strip().split(",")[0]
            list_ID_s.append(ID_s)

    with open("passed.txt","r") as fp:
        content_p=fp.readlines()
        num_lines_p = len(content_p)
        fp.seek(0)  
        for i in range(num_lines_p):
            ID_p = fp.readline().strip().split(",")[1]
            list_ID_p.append(ID_p)

    with open("courses.txt","r") as fp:
        content_c=fp.readlines()
        num_lines_c = len(content_c)
        fp.seek(0)  
        for i in range(num_lines_c):
            ID_c = fp.readline().strip().split(",")[0]
            list_ID_c.append(ID_c)
    
    student_ID=input("Student ID: ")

    if student_ID in list_ID_s:
        for i in range(len(list_ID_s)):
            if student_ID == list_ID_s[i]:
                need_lines_s.append(i)
        s=need_lines_s[0]
        student_data = content_s[s].strip().split(",")
        print("Name: ",student_data[2],", ",student_data[1],sep="")
        print("Starting year:",student_data[3])
        if student_data[4]=="CE":
            print("Major: Computational Engineering")
        elif student_data[4]=="EE":
            print("Major: Electrical Engineering")
        elif student_data[4]=="ET":
            print("Major: Energy Technology")
        elif student_data[4]=="ME":
            print("Major: Mechanical Engineering")
        elif student_data[4]=="SE":
            print("Major: Software Engineering")
        print("Email:",student_data[5],"\n")
        print("Passed courses:\n")

        credit_total=0
        grade_total=0
        for i in range(len(list_ID_p)):
            if student_ID == list_ID_p[i]:
                need_lines_p.append(i)
        

        for i in need_lines_p:
            passed_data = content_p[i].strip().split(",")
            Courses_ID=passed_data[0]
            Date=passed_data[2]
            grade=passed_data[3]

            for j  in  range(len(list_ID_c)):
                if Courses_ID == list_ID_c[j]:
                    need_lines_c.append(j)

            for k in need_lines_c:
                course_data = content_c[k].strip().split(",")
            Course_name=course_data[1]
            Credits=course_data[2]
            credit_total+=int(Credits)
            grade_total+=int(grade)

            for i in need_lines_p:
                average=grade_total/len(need_lines_p)
                data_teachers=course_data[3:]
                teachers=', '.join(element.strip() for element in data_teachers)




            print("Course ID: ",Courses_ID,", Name: ",Course_name,", Credits: ",Credits,"\n""Date: ",Date,", Teacher(s): ",teachers,", grade: ",grade,"\n",sep="")
        print("Total credits: ",credit_total,", average grade: ",average,sep="")

    else :
        print("Wrong student ID!")



menu()