Creating a calculation based on user entry

[blakefindlay]

I am only days new to python so please bear with me.

The issue I think I am running into is that when I launch the script, python immediately gets the entry which is nothing at launch. I want to input an entry for the # of days for the rental and than get that and create a calculation so I can output the cost on the screen.

Any help would be much appreciated.

from tkinter import *

root = Tk()

#Welcome message
welcome_label = Label(root, text="Overlander Sports Rental Form")
welcome_label.grid(row=1, column=2)

#Entry line for employee name
ename = Entry(root)
ename.grid(row=2, column=2)

#Label for employee entry line
ename_label = Label(root, text="Employee Name: ")
ename_label.grid(row=2, column=1)

flname = Entry(root)
flname.grid(row=3, column=2)

flname_label = Label(root, text="Renter's Name: ")
flname_label.grid(row=3, column=1)

rental_period = Entry(root)
rental_period.grid(row=4, column=2)

rental_period_label = Label(root, text="Renting for # of days: ")
rental_period_label.grid(row=4, column=1)


def myclick():
    mylabel = Label(root, text="Saved!")
    mylabel.grid(row=5, column=3)
    test_renter = open("test_file", "w")
    test_renter.write("Employee Name: " + ename.get())
    test_renter.write("\n")
    test_renter.write("Renter's Name: " + flname.get())
    test_renter.write("\n")
    test_renter.write("Renting for: " + str(rental_period.get()) + " days")
    test_renter.write("\n")

    rental_period.get()
    print(rental_period)

    test_renter.close()


save_button = Button(root, text="Save", command=myclick, fg="blue")
save_button.grid(row=5, column=2)

root.mainloop()