Command Line application through python

#Bank management system

import getpass
import sys

User_Db = {'sanpai':'Admin123','anabharat':'Admin1234'}
count = 0

def logon(User_Db):

    u_name=input("Enter the username : ")
    print("\n")
    p_word=getpass.getpass("Enter Password : ")
    print("\n")

    return User_Db.get(u_name,None) == p_word
   # print(u_name)
   # print (p_word)


for r in range(20):
    print("*",end=" ")

print("\n")
print("\t  WELCOME TO BMS   \t",end = " ")

print("\n")
for r in range(20):
    print("*",end=" ")

print("\n")

for i in range(3):
	if logon(User_Db):
		print ("Authentication Successful ...")
		print ("\n")
		break
	else:
		if count == 2:
			print ("Account Locked Contact Admin ")
			print("\n")
			sys.exit()
		else:
			print ("Authentication failure please relogin ")
			print("\n")
	count+=1


for r in range(20):
    print("*",end=" ")

print("\n")

while True:

    print("1. ACCOUNT ")
    print("2. TRANSCATIONS ")
    print("3. REPORTS ")
    print("4. EXIT ")

    print("\n")

    try:
        choice=int(input("Enter Your choice  : "))
    except ValueError:
        print("Enter a choice between 1 and 4")


    if choice == 1:
        while True:

            print("1. Add Account")
            print("2. Update Account ")
            print("3. Delete Account ")
            print("4. Goto Main Menu ")
            print("5. Exit ")

            try:
                choice=int(input("Enter Your choice  : "))
            except ValueError:
                print("Enter a choice between 1 and 5")

            if choice == 1:
                try:
                    fp = open("Accounts.txt","a")
                except IOError:
                    print("File error , try again")

                Name = input("Enter your name : ")
                Mob_num = input ("Enter Mobile number : ")

                fp.write('%s \t\t %s \t\t %d \t\n'%(Name,Mob_num,0))

                print("account added succesfully ,maintain an minimum balance of INR 3000")
                fp.close()

            elif choice == 2:
                print("To be done ")

            elif choice == 3:
                print("To be done ")

            elif choice == 4:
                print("To be done ")

            elif choice == 5:
                 sys.exit()
            else:
                print("Enter a choice between 1 and 5")

    elif choice == 2:
        print("1. Deposit")
        print("2. Withdraw ")
        print("3. Goto Main Menu ")
        print("4. Exit")

        try:
            ch=int(input("Enter Your choice  : "))
        except ValueError:
            print("Enter a choice between 1 and 4")
    elif choice == 3:
        print("Reports")

    elif choice == 4:
        sys.exit()

    else:
        print("Enter a choice between 1 and 4")