Return_gui.py

import tkinter as t
from tkinter import scrolledtext as sct
from tkinter import messagebox,DoubleVar,ttk
import ListSplit_gui as ListSplit
import Borrow_details as BD

#these widgets and variables are declared global because they are 
#used in multiple methods
global entry1,entry3
global entry2
global combo1
global scrollt
global btn
global btn1
global book_counter

book_counter=0

entry1=t.Entry()
entry2=t.Entry()
entry3=t.Entry()

btn=t.Button()
btn1=t.Button()

combo1=ttk.Combobox()
scrollt=sct.ScrolledText()

entry1_v=DoubleVar
entry2_v=DoubleVar
entry3_v=t.IntVar

#every global variable must be initialized before using
book_list=ListSplit.listSplit()

#r_window method generates the window used for book returning 
def r_window():
    global entry1
    global entry2
    global entry3
    global combo1
    global scrollt
    global btn
    global btn1
    
    book_counter=0

    window=t.Tk()
    window.geometry("530x450")
    window.title("Library management system")
    window.resizable(0,1)

    l1=t.Label(window,text="First Name",width=10).grid(row=0,pady=2,padx=4)

    entry1=t.Entry(window,width=30,textvariable=entry1_v)
    entry1.grid(row=0,column=1)

    l2=t.Label(window,text="Last Name",width=10).grid(row=1,pady=2,padx=4)

    entry2=t.Entry(window,width=30,textvariable=entry2_v)
    entry2.grid(row=1,column=1)

    btn=t.Button(window,text="Validate",command=validate,width=20)#validate() will be invoked when this button is clicked
    btn.grid(row=2,columnspan=2,pady=5,padx=4)

    scrollt=sct.ScrolledText(window,width=60,height=10)
    scrollt.grid(row=4,rowspan=4,columnspan=3,padx=20,pady=2)

    l3=t.Label(window,text="how many days was the book returned late").grid(row=8,pady=2,padx=4)

    entry3=t.Entry(window,width=30,textvariable=entry3_v)
    entry3.grid(row=8,column=1)

    btn1=t.Button(window,text="Return",command=book_return,state=t.DISABLED,width=20)#winodw will be destroyed when this button is clicked
    btn1.grid(row=9,columnspan=2,pady=2,padx=4)

    window.mainloop()

#validate method is used to validate the returner's name and create his file 
def validate():
        global entry1
        global entry2
        global combo1
        global scrollt
        global btn,btn1

        #retriving text entered in entry
        firstName=str(entry1.get())
        lastName=str(entry2.get())

        a="F:\python projects\LMS\Borrow-"+firstName+" "+lastName+".txt"
        b="F:\python projects\LMS\Return-"+firstName+" "+lastName+".txt"

        #checking if the firstname and lastname contains only charachters and not numbers 
        if firstName.isalpha() and lastName.isalpha():
            
            #checking if the user has borrowed any books or not
            
            try:
                #checking if borrowers file exists
                with open(a,"r") as f:
                    lines=f.readlines()
                    
                #opening borrowers file
                with open(a,"r") as f:
                    scrollt.delete(1.0,float(2000))
                    scrollt.update()
                    data=f.read()
                    scrollt.insert(t.INSERT,data)
                    t.messagebox.showinfo(message="File Opened successfully")

                   #checking if the borrower has returned the books or not
                    
                    try:
                        #checking if returner's file exists
                        with open(b,"r") as f:
                            lines=f.readlines()
                            
                        #opening the return and borrow files of user
                        with open(b,"r") as f,open(a,"r") as f1:
                            scrollt.delete(1.0,float(2000))
                            scrollt.update()
                            data=f1.read()
                            scrollt.insert(t.INSERT,data)
                            scrollt.insert(t.INSERT,"\n-------------------------------------------------------\n")
                            data1=f.read()
                            scrollt.insert(t.INSERT,data1)
                            t.messagebox.showinfo(message="The borrower has already returned the books")
                            
                    except:
                        t.messagebox.showwarning(message="The borrower has not returned the books")
                        #activating the return button as borrower has not returned the books
                        btn1['state']=t.NORMAL
            except:
                #if borrower's file does not exists the name will be incorrect
                t.messagebox.showwarning(message="The borrower name is incorrect")
                
        else:
            t.messagebox.showwarning(message="please input only alphabets from A-Z")

def book_return():

    global entry1
    global entry2,entry3
    global combo1
    global scrollt
    global btn,btn1
 
    firstName=str(entry1.get())
    lastName=str(entry2.get())

    a="F:\python projects\LMS\Borrow-"+firstName+" "+lastName+".txt"
    b="F:\python projects\LMS\Return-"+firstName+" "+lastName+".txt"
   
    #reading users book borrow file
    with open(a,"r") as f1:
        data2=f1.read()

    #creating users book return file
    with open(b,"w+")as f:
        f.write("                Library Management System \n")
        f.write("                   Returned By: "+ firstName+" "+lastName+"\n")
        f.write("S.N.\t\tBookname\t\tCost\n")
    total=0.0

    book_borrowed=BD.borrow_details(firstName,lastName)
    count=0
    for i in book_borrowed:
        for j in range(ListSplit.count1):
            if i == ListSplit.bookname[j]:
                count+=1
                with open(b,"a") as f:
                    f.write(str(count)+"\t\t"+ListSplit.bookname[j]+"\t\tRs"+ListSplit.cost[j]+"\n")
                    #adding 1 to book quntity on return
                ListSplit.quantity[j]=int(ListSplit.quantity[j])+1
                total+=float(ListSplit.cost[j])

    
    if len(entry3.get()) == 0:
        day=0
    else:
        day=int(entry3.get())
    fine=5*day

    #appending the fine to the users book return file 
    with open(b,"a")as f:
        f.write("\t\t\t\t\tFine: Rs"+ str(fine)+"\n")
    total=total+fine
    
    t.messagebox.showinfo(title="Overflow",message="Total bill:"+str(total))

    #appending the total cost to the users book return file 
    with open(b,"a")as f:
        f.write("\t\t\t\t\tTotal: Rs"+ str(total))
    
    #rewriting stocks after return of book
    with open("F:\python projects\LMS\Stock.txt","w+") as f:
            for i in range(ListSplit.count1):
                f.write(ListSplit.bookname[i]+","+ListSplit.authorname[i]+","+str(ListSplit.quantity[i])+","+"Rs"+ListSplit.cost[i]+"\n")

    #displaying the book return file of user in scrolledtext
    b="F:\python projects\LMS\Return-"+firstName+" "+lastName+".txt"
    with open(b,"r") as f:
                scrollt.delete(1.0,float(2000))
                scrollt.update()
                data=f.read()
                scrollt.insert(t.INSERT,data)


    #when user returns the books the return button will be disabled
    btn1['state']=t.DISABLED