tkinter, how to get the value of an Entry widget? [duplicate]

Question

I'm trying to offer the user the possibility to calculate his profit of his projected sales if the margin has a certain value (.23). The user should be able to enter any value as projected sales:

from tkinter import *

root = Tk()

margin = 0.23
projectedSales = #value of entry
profit = margin * int(projectedSales)

#My function that is linked to the event of my button
def profit_calculator(event):
    print(profit)


#the structure of the window
label_pan = Label(root, text="Projected annual sales:")
label_profit = Label(root, text="Projected profit")
label_result = Label(root, text=(profit), fg="red")

entry = Entry(root)

button_calc = Button(root, text= "Calculate", command=profit_calculator)
button_calc.bind("<Button-1>", profit_calculator)

#position of the elements on the window
label_pan.grid(row=0)
entry.grid(row=0, column=1)
button_calc.grid(row=1)              
label_profit.grid(row=2)
label_result.grid(row=2, column=1)

root.mainloop()

Answer 1

You can get what's inside Entry widget using get method like:

entry = tkinter.Entry(root)
entryString = entry.get()

Here's an example that does around what you want:

import tkinter as tk

root = tk.Tk()

margin = 0.23

entry = tk.Entry(root)

entry.pack()

def profit_calculator():
    profit = margin * int(entry.get())
    print(profit)

button_calc = tk.Button(root, text="Calculate", command=profit_calculator)
button_calc.pack()

root.mainloop()

You may also want to use textvariable option and tkinter.IntVar() class for synchronizing integer texts for multiple widgets like:

import tkinter as tk

root = tk.Tk()

margin = 0.23
projectedSales = tk.IntVar()
profit = tk.IntVar()

entry = tk.Entry(root, textvariable=projectedSales)

entry.pack()

def profit_calculator():
    profit.set(margin * projectedSales.get())

labelProSales = tk.Label(root, textvariable=projectedSales)
labelProSales.pack()

labelProfit = tk.Label(root, textvariable=profit)
labelProfit.pack()

button_calc = tk.Button(root, text="Calculate", command=profit_calculator)
button_calc.pack()

root.mainloop()

Above example shows that labelProSales and entry have their text values equal at all times, as both use the same variable, projectedSales, as their textvariable option.