Having trouble receiving Data from Tkinter Entry widget Python 3

Question

I am trying to implement a login system for a program I am making. The issue is in trying to retrieve the input and store it in a variable when the user clicks submit.

I have already read several articles on this, but none seem to work. The following has program has had several section removed, but encounters the same issue.

#Imports
import tkinter

#Initilization
master = tkinter.Tk()

#Defineing Variables

#Submit
def Submit():
    print("Creating Account...")
    master.destroy()

#Cancel
def Cancel():
    print("Login failed!")
    master.destroy()

#Build GUI
def BuildGUI():
    #Lables
    tkinter.Label(master, text="All avalibe feilds required.").grid(row=0)

    tkinter.Label(master, text="First Name").grid(row=1)

    #Input Fileds
    User_NameFirst = tkinter.StringVar()

    e1 = tkinter.Entry(master, textvariable=User_NameFirst)

    e1.grid(row=1, column=1)

    #Buttons
    tkinter.Button(master, text='Cancel', command=Cancel).grid(row=11, column=0, sticky='W', pady=4)
    tkinter.Button(master, text='Enter', command=Submit).grid(row=11, column=1, sticky='W', pady=4)
    tkinter.Button(master, text='Test', command=print(e1.get())).grid(row=12, sticky='W', pady=6, padx=6)

#Debug
BuildGUI()

#Mainloop
tkinter.mainloop()

I expected, that when I click "test", that the program would print the value that I imputed into e1 to be printed. However, nothing happens. I did notice that, when I start the program, the terminal seems output a few blank lines.

Read [Why is Button parameter “command” executed when declared?](https://stackoverflow.com/questions/5767228/why-is-button-parameter-command-executed-when-declared) — Henry Yik, Apr 23 '19 at 03:16

score 0 · Accepted Answer · edited Apr 23 '19 at 14:34

0

The comment by Henry Yik is correct- as demonstrated by https://stackoverflow.com/a/5771787/11006183, The print() statement was executed before I clicked the button.

To fix it, I needed to use the lambda function:

tkinter.Button(master, text='Test', command=lambda: print(e1.get()) ).grid(row=12, sticky='W', pady=6, padx=6)

edited Apr 23 '19 at 14:34

Saad

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answered Apr 23 '19 at 05:28

BobSaidHi

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You don't have to put the `print` function in a list. `command=lambda: print(e1.get())` work just fine – Henry Yik Apr 23 '19 at 07:32

Having trouble receiving Data from Tkinter Entry widget Python 3

1 Answers1