from tkinter import *
from tkinter import ttk

def clear():
    e1.delete(0,END)
    e3.delete(0,END)

def convert():
    var2 = indicator.get()
    var3 = var1.get()
    if var2 == 'China':
        e3.delete(0,END)
        var4 = ((var3*6.88),'Yuan')
        e3.insert(0,var4)
    elif var2 == 'France':
        e3.delete(0,END)
        var4 = ((var3*0.81),'Euro')
        e3.insert(0,var4)
    elif var2 == 'Ghana':
        e3.delete(0,END)
        var4 = ((var3*4.88),'Cedi')
        e3.insert(0,var4)
    elif var2 == 'Mexico':
        e3.delete(0,END)
        var4 = ((var3*18.90),'MXN')
        e3.insert(0,var4)
    elif var2 == 'Nigeria':
        e3.delete(0,END)
        var4 = ((var3*360.01),'Naira')
        e3.insert(0,var4)
    elif var2 == 'USA':
        e3.delete(0,END)
        var4 = ((var3*1.00),'USD')
        e3.insert(0,var4)
    else:
        e3.delete(0,END)
        var4 = ('Error: Please, choose a country')
        e3.insert(var4)


root = Tk()
root.title('Currency converter')

var1 = IntVar()
indicator = StringVar(value='Choose a country')

Label(text='Currency Converter',padx=10,font=('arial', 16,'bold')).grid(row=0,column=1)

Label(text='Amount ($)',padx=10,font=('arial', 16,'bold')).grid(row=1,sticky=W)
e1 = Entry(width=17,font=('arial', 16,'bold'), textvariable=var1)
e1.grid(row=1,column=1)

Label(text='Country',padx=10,font=('arial', 16,'bold')).grid(row=2,sticky=W)
e2 = ttk.Combobox(width=15,font=('arial', 16,'bold'),textvariable=indicator)
e2['values'] = ('China', 'France', 'Ghana', 'Mexico', 'Nigeria', 'USA')
e2.grid(row=2,column=1)

Label(text='Total',padx=10,font=('arial', 16,'bold'),fg='red').grid(row=3,sticky=W)
e3 = Entry(width=17,font=('arial', 16,'bold'))
e3.grid(row=3,column=1)

Button(text='Convert',font=('arial', 10,'bold'),width=12, command=convert).grid(row=4,column=1,sticky=W)
Button(text='Clear',font=('arial', 10,'bold'),width=12, command=clear).grid(row=4,column=1,sticky=E)

root.mainloop()