1, Program function

1. Overview

Using Python to complete a program for adding, deleting, modifying and checking student information mainly involves knowledge points: program control structure (realizing multi-level menus that can be advanced and retreated), file reading and writing operation (student information should be saved in files on disk), and function modularization by using functions.

2. Mind map

2, Student entity

1. Mind map

2. Relational model

• Student (student number, name, gender, age, class, major, Department, telephone)

3. Student list

• Line record Yuanzu
• Column - field - attribute

Student number	full name	Gender	Age	class	major	Department	Telephone
2021001	Xiao Xiaohan	female	19	2021 software technology class 4	Software technology	College of artificial intelligence and big data	12894763846
2021002	Li Xiaohong	female	18	2021 software technology class 4	Software technology	College of artificial intelligence and big data	18273649304
2021003	Tang Lilin	female	19	2021 software technology class 4	Software technology	College of artificial intelligence and big data	13762738377
2021004	Xiao Haoyu	male	20	2021 big data class 1	Software technology	College of artificial intelligence and big data	18987876361
2021005	Xiao Gang Wang	male	18	2021 big data class 1	Software technology	College of artificial intelligence and big data	13678363763
2021006	Zhang Sanfeng	male	20	2021 big data class 1	Software technology	College of artificial intelligence and big data	15887367678

• First save the student information to a text file and separate each field with a space.
  

• If you use the notepad that comes with your computer, you need to change the code to ANSI. The specific steps are as follows:

• 1) Save the saved text file as
  

• 2) Change encoding to ANSI
  

3, Read student files

• The file structure is composed of several lines and columns, which are read line by line. The string read from each line is divided into a tuple through spaces. After all lines are read, it will naturally form a list of tuples.

1. Save multiple student information with Yuanzu's list

• establish

• Operation results
  

2. Read the student file data and save it to the list of tuples

• establish
  

• Operation results
  

• Format output students list
  

• Operation results
  

4, Add, delete, modify and query the list of student tuples

1. Add student records

• Add a new student tuple

Student number	full name	Gender	Age	class	major	Department	Telephone
2021007	Xiao Yang	male	20	2021 big data class 1	Big data technology	College of artificial intelligence and big data	18273645767

• Operation results
  

2. Query student records

1) Query student records by student number

• Operation results
  

2) Find student records by name

• Operation results
  
• Find by other attributes, and so on

3. Modify student records

• Operation results
  

4. Delete student record

• Operation results
  

5, Writes a list of student tuples to a file

• Operation results
  
• View written files
  

6, Constructing a multi-level menu system for student information management

1. Build a multi-level menu system

• Operation results
  

2. Realize the student information management function module

1) Write and query all student records

to write:

• get_all_students() function
• display_all_students() function
  
• Operation results
  

2) Write and add student record function

to write

• add_student() function
  
• Operation results
  
• Check the new record in Notepad
  

3) Function of compiling and modifying student records

to write

• modify_student() function
• Modify the student's age and phone number
  
• Operation results
  
• If the student number does not exist
  

4) Write and delete student records

to write

• delete_student() function
  
• Operation results
  
• Check the new record in Notepad
  
• Delete succeeded

5) Write the function of querying student records by student number

to write

• display_id_student() function
  
• Run code
  

6) Write the function of querying student records by name

to write

• display_name_student() function
  
• Operation results
  

7, Student information management procedure

• code

# -*- coding: utf-8 -*-
"""
Function: student information management
 Author: Xiao Rong
 Date: December 28, 2021
"""

def get_all_student():
    students =[]
    f = open('student.txt')
    for line in f:
        line = line.replace('\n', ' ')
        student = line.split(' ')
        students.append(student)
    f.close()
    return students


def add_student():
    students = get_all_student()
    
    id = input('Student No.:')
    name = input('full name:')
    gender = input('Gender:')
    age = input('Age:')
    clas = input('Class:')
    major = input('Major:')
    department = input('Department:')
    telephone = input('Telephone:')
    
    students.append([id, name, gender, age, clas, major, department, telephone])
    
    f = open('student.txt', 'w')
    for i in range(len(students)):
        student = ' '.join(students[i]) + '\n'
        f.write(student)
    f.close()
    print('\n Congratulations, student record added successfully!\n')


def display_all_student():
    students = get_all_student()
    for i in range(len(students)):
        for j in range(len(students)):
            print(students[i][j], end= ' ')
        print()


def display_id_student():
    students = get_all_student()
    f = open('student.txt')
    id = input('Please enter the student number to query:')
    found = False
    for student in students:
        if (student[0] == id):
            found = True
            for i in range(len(student)):
                print(student[i], end=' ')
            break
    
    if not found:
        print('Student number is[{}]My students didn't find it!'.format(id))


def display_name_student():
    students = get_all_student()
    f = open('student.txt')
    name = input('Please enter the name of the student to be checked:')
    found = False
    for student in students:
        if (student[1] == name):
            found = True
            for i in range(len(student)):
                print(student[i], end=' ')
            break
    
    if not found:
        print('Name is[{}]My students didn't find it!'.format(name))
        
        

def query_student():
    while True:
        print('Query student records')
        print('=' * 20)
        print('1.Query student records by student number')
        print('2.Query student records by name')
        print('3.Query all student records')
        print('4.Return to the previous menu')
        print('=' * 20)
        mc3 = int(input('Enter menu number:'))
        if mc3 == 1:
            display_id_student()
        elif mc3 == 2:
           display_name_student()
        elif mc3 == 3:
            display_all_student()
        else:
            break

def modify_student():
    students = get_all_student()
    
    f = open('student.txt','w')
    
    id = input('Enter the student number of the student to be changed:')
    found = False
    for student in students:
        if (student[0] == id):
            found = True
            student = list(student)
            new_age = input('Enter a new age:')
            new_telephone = input('Enter a new phone number:')
            student[3] = new_age
            student[7] = new_telephone
            student = tuple(student)
            print('Congratulations: student record modified successfully!')
            break
    if not found:
        print('Student number is[{}]My students didn't find it!'.format(id))
        
    for i in range(len(students)):
        student = ' '.join(students[i]) + '\n'
        f.write(student)
    f.close()

def delete_student():
    students = get_all_student()
    f = open('student.txt', 'w')
    id = input('Enter the student number to be deleted:')
    found = False
    for student in students:
        if (student[0] == id):
            found = True
            students.remove(student)
            print('Delete record succeeded!')
            break
    if not found:
        print('Student number is[{}]My students didn't find it!'.format(id))
    for i in range(len(students)):
        student = ' '.join(students[i]) + '\n'
        f.write(student)
    f.close()





def login():
    username = input('Enter user name:')
    password = input('Input password:')
    if username == 'xiaoxiaorong' and password == '202542':
        while True:
            print('Student information management')
            print('=' * 20)
            print('1.Add student records')
            print('2.Query student records')
            print('3.Modify student records')
            print('4.Delete student record')
            print('5.Previous Menu ')
            print('=' * 20)
            mc2 = int(input('Enter menu number:'))
            if mc2 == 1:
                add_student()
            elif mc2 == 2:
                query_student()
            elif mc2 == 3:
                modify_student()
            elif mc2 == 4:
                delete_student()
            else:
                break
    else:
        print('\n The user name or password is incorrect. Please log in again\n')

while True:
    print('User login')
    print('=' * 20)
    print('1.Sign in')
    print('2.sign out')
    print('=' * 20)
    mc1 = int(input('Enter menu number:'))
    if mc1 == 1:
        login()
    elif mc1 == 2:
        print('\n Thank you for using this program!\n')
        break