CODEWITHSUNDEEP
pythontkinter
user16055650
user16055650

Reputation:

How can I disable the the button? (GUI)

I'm making simple calculator and I've implemented all the functions except one function. As you know, dots must be used only once until the new number comes. So I want to make the (.) button disabled after used once and make it available again when I use symbol or C. I was thinking about changing the button text by using configure method.

Here's my code:

from tkinter import*
w1 = Tk()
w1.title("My Calculator") 
show = Entry(w1, width=33, bg="yellow") 
show.grid(row=0, column=0, columnspan=5)
btn_list = [ 
    '7','8','9','/','C',
    '4','5','6','*','',
    '1','2','3','-','',
    '0','.','=','+','']
index_row = 1 
index_col = 0 
def click(button): 
    if button == "=":  
        value = eval(show.get()) 
        s = str(value) 
        show.delete(0,"end") 
        show.insert(END,s) 
    elif button=="C": 
        show.delete(0,"end") 
    else: 
        show.insert(END,button) 
for btn_text in btn_list: 
    def go(k=btn_text): 
        click(k)
    Button(
        w1, text=btn_text, width=5, command=go
    ).grid(row=index_row, column=index_col) 
    index_col += 1 
    if index_col > 4: 
        index_row += 1  
        index_col = 0

w1.mainloop()

Upvotes: 2

Views: 352

Answers (1)

Delrius Euphoria
Delrius Euphoria

Reputation: 15088

Easiest way is to use a tkinter variable and trace it.

var = StringVar()
show = Entry(w1, width=33, bg="yellow", textvariable=var) 

def validate(*args):
    if var.get().count('.') > 1:
        var.set(var.get()[:-1])

var.trace('w',validate)

There are more than just one way to do this, starting with storing input in the list, or storing the specific button as a variable and so on. There are also different ways to loop through the texts easily.

Updated because your professor has not taught you the previous method(yet):

def click(button): 
    ..... # Same stuff

    if show.get().count('.') >= 1:
        dot_btn.config(state='disabled')
    else:
        dot_btn.config(state='normal')

for btn_text in btn_list: 
    def go(k=btn_text): 
        click(k)
    if btn_text == '.':
        dot_btn = Button(w1, text=btn_text, width=5, command=go)
        dot_btn.grid(row=index_row, column=index_col) 
    else:
        Button(
            w1, text=btn_text, width=5, command=go
        ).grid(row=index_row, column=index_col) 
    index_col += 1 
    if index_col > 4: 
        index_row += 1  
        index_col = 0

This looping method is really beating around the bush, directly you could just use nested loops and get your desired output, you would not even need to made index_row and index_col. Never limit your understanding to what your professor or mentor has taught you, be ready to explore and learn more(maybe you will end up teaching him :P).

Note that using eval() to do mathematical expressions alone is poor, it opens a whole new galaxy of security issues.

Upvotes: 0

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