ValueError：int() 的无效文字，基数为 10: '' (Tkinter)

Question

When I try to run this code, a ValueError appears alluding to the function numRandom . I though Python could pass a string representation of a int to an int .

import tkinter
import random

window = tkinter.Tk()
window.geometry('600x500')

x = random.randint(1,300)
remainingTime = True
Attempts = 4

def numRamdom():
    global Attempts
    while Attempts > 0:
        numWritten = int(entryWriteNumber.get())
        if numWritten > x:
            lblClue.configure(text = 'Its a bigger number')
            Attempts = Attempts -1
        if numWritten < x:
            lblClue.configure(text = 'Its a smaller number')
            Attempts = Attempts -1
        if numWritten == x:
            lblClue.configure(text = 'Congratulations ;)')
            remainingTime = False
            return remainingTime, countdown(0)
        if Attempts == 0:
            remainingTime = False
            return remainingTime, countdown(0), Attempts, gameOver()

entryWriteNumber = tkinter.Entry(window)
entryWriteNumber.grid(column = 0, row = 1, padx = 10, pady = 10)

numRamdom()

window.mainloop()

Answer 1

The problem is because when the code is ran, it directly calls numRamdom() , that is, initially the entry widgets are empty, and they run it with those empty entry widget and hence the error. So just assign a button and a command, like:

b = tkinter.Button(root,text='Click me',command=numRamdom)
b.grid(row=1,column=0)

Make sure to say this before the mainloop() after the def numRamdom(): . The button just runs the function only when the button is clicked.

Or if you want button-less then try:

METHOD-1:

root.after(5000,numRamdom) #after 5 sec it will execute function

But keep in mind, if the user doesn't enter properly in 5 sec then some error would pop up.

METHOD-2:

def numRamdom(event):
......

entryWriteNumber.bind('<Return>',numRamdom)

This is so that, if you press enter key in the entry widget(after entering data) it will run the function.

Hope this helps, do let me know if any errors.

Cheers

Answer 2

Here's a fully working example based on your code. Your problem was trying to convert the contents of the Entry before anything was inside of it. To fix this problem, you can add a button which calls the command numRamdom()

import tkinter
import random

window = tkinter.Tk()
window.geometry('600x500')

x = random.randint(1,300)
remainingTime = True
Attempts = 4

def numRamdom():
    global Attempts, lblClue, x
    if Attempts > 0:
            numWritten = int(entryWriteNumber.get())
            if numWritten < x:
                lblClue.configure(text = 'Its a bigger number')
                Attempts = Attempts -1
            elif numWritten > x:
                lblClue.configure(text = 'Its a smaller number')
                Attempts = Attempts -1
            else:
                lblClue.configure(text = 'Congratulations ;)')
                remainingTime = False
                #return remainingTime, countdown(0)
            if Attempts == 0:
                remainingTime = False
                #return remainingTime, countdown(0), Attempts, gameOver()
    else:
        lblClue.configure(text = "You ran out of attempts!")

entryWriteNumber = tkinter.Entry(window)
entryWriteNumber.grid(column = 0, row = 1, padx = 10, pady = 10)

entryWriteButton = tkinter.Button(window, text = "Push me!", command = numRamdom)
entryWriteButton.grid(column = 1, row = 1)

lblClue = tkinter.Label(window)
lblClue.grid(row = 2, column = 1)


window.mainloop()

You'll still get an error if the value passed is not able to be converted into an integer, but that's easy to fix with an if statement.