renew.py

from tkinter import *
from tkinter import messagebox
import sqlite3
from sqlite3 import Error
from datetime import datetime,date
import os
import sys
py = sys.executable


class renew(Tk):
    def __init__(self):
        super().__init__()
        self.iconbitmap(r'libico.ico')
        self.title("Renew")
        self.maxsize(600,400)
        self.minsize(600, 400)
        a = StringVar()
        b = StringVar()
        self.cal = 0

        def days_between(d1, d2):
            d1 = datetime.strptime(d1, "%Y-%m-%d")
            d2 = datetime.strptime(d2, "%Y-%m-%d")
            return abs((d2 - d1).days)

        def qui():
            if len(a.get()) == 0 or len(b.get()) == 0:
                messagebox.showerror("Error","Please Enter The Id's")
            else:
                try:
                    self.conn = sqlite3.connect('library_administration.db')
                    self.mycursor = self.conn.cursor()
                    self.mycursor.execute("Select BID from issue where BID = ?",[a.get()])
                    temp = self.mycursor.fetchone()
                    self.mycursor.execute("Select Fine from students where Student_Id = ?", [b.get()])
                    fine = self.mycursor.fetchone()
                    self.mycursor.execute("Select Return_date from issue where BID = ? and SID = ?", [a.get(), b.get()])
                    temp1 = self.mycursor.fetchone()
                    if temp1:
                        da = str(date.today())
                        ea = str(temp1[0])
                        if da < ea:
                            messagebox.showinfo("Oops", "Your Return Date Has not yet come")
                        else:
                            self.cal = days_between(ea, da)
                            self.cal += int(fine[0])
                        if int(self.cal) >= 100:
                            messagebox.showinfo("Fine", "Your Id is banned.Please pay the fine")
                        elif int(self.cal) > 0:
                            messagebox.showinfo('Warning','Please Return/Renew book Timely to avoid termination of id')
                            self.mycursor.execute("Update students set Fine = ? where Student_Id = ?",[int(self.cal), b.get()])
                            self.mycursor.execute("UPDATE issue set Issue_date = date('now') where BID =? ", [a.get()])
                            self.mycursor.execute("update issue set Return_date = date('now','+15 days') where BID = ?",[a.get()])
                            self.conn.commit()
                            self.conn.close()
                            messagebox.showinfo('Info', 'Succesfully Renewed')
                            c = messagebox.askyesno("Confirm", "Do you want to renew another book?")
                            if c:
                                self.destroy()
                                os.system('%s %s' % (py, 'renew.py'))
                            else:
                                self.destroy()
                    else:
                        messagebox.showinfo("Oop's", "The Book is not yet issued")
                except TypeError:
                  messagebox.showerror("Error", "Check The Texts")
                except Error:
                    messagebox.showerror("Error","Check The Fields")

        Label(self, text='Renew Book',  fg='red',font=('arial', 35, 'bold')).pack()
        Label(self, text='Enter Book ID',font=('Comic Scan Ms', 15, 'bold')).place(x=80, y=150)
        Entry(self, textvariable=a, width=40).place(x=280, y=150)
        Label(self, text="Enter Student Id",font=('Comic Scan Ms', 15, 'bold')).place(x=80, y=200)
        Entry(self, textvariable=b, width=40).place(x=280, y=200)
        Button(self, text="Renew", width=25, command=qui).place(x=280, y=300)

renew().mainloop()