Changing variable using entry and button TKinter, tax calculator

Question

Attempting to make a tax calculator and I have been struggling to work out how to make it so that the variable (salary) can change using an input in an entry box and a button to confirm the entry. I'm not sure if its my layout or that I am missing something (probably obvious).

I am sure that it is something to do with the command as the error code: TypeError: int() argument must be a string, a bytes-like object or a real number, not 'Entry' comes up when it runs.

If the salary variable is changed in the code itself everything seems to add up, so its just how to tie it all together.

so this is the code that I have done so far:

import tkinter as tk

salary = 1

window = tk.Tk()

title = tk.Label(text="Salary Calculator")
title.grid(column=1, row=0)

canvas = tk.Canvas(width=300, height=300, bg="black",)
canvas.grid(column=1, row=1)

gross_wage_title = tk.Label(text="Enter gross wage: £")
tax_band_title = tk.Label(text="Your Tax band is: ")
taxation_title = tk.Label(text="Amount to pay in tax: £")
yearly_net_wage_title = tk.Label(text="Your yearly net wage will be: £")
monthly_net_wage_title = tk.Label(text="Your monthly net wage will be: £")

gross_wage_title.grid(column=0, row=2, columnspan=2)
tax_band_title.grid(column=0, row=3, columnspan=2)
taxation_title.grid(column=0, row=4, columnspan=2)
yearly_net_wage_title.grid(column=0, row=5, columnspan=2)
monthly_net_wage_title.grid(column=0, row=6, columnspan=2)

def gross_salary():
    global salary
    salary = int(gross_wage_input)

gross_wage_input = tk.Entry()
gross_wage_input.grid(column=2, row=2)

calculate = tk.Button(text="Calculate", command=gross_salary)
calculate.grid(column=2, row=7)

# ------------------------------------------------------------------ #
salary = 0
if salary < 12570:
    tax = 0
    band = "No Rate"
    keep = salary
elif int(salary) in range(12570, 14732):
    tax = 19
    band = "Starter Rate"
    taxable = round((int(salary)/100) * tax, 2)
    keep = round(int(salary) - taxable, 2)
elif int(salary) in range(14733, 25688):
    tax = 20
    band = "Basic Rate"
    taxable = round((int(salary)/100) * tax, 2)
    keep = round(int(salary) - taxable, 2)
elif int(salary) in range(25689, 43662):
    tax = 21
    band = "Intermediate Rate"
    taxable = round((int(salary)/100) * tax, 2)
    keep = round(int(salary) - taxable, 2)
elif int(salary) in range(43663, 125140):
    tax = 42
    band = "Higher Rate"
    taxable = round((int(salary)/100) * tax, 2)
    keep = round(int(salary) - taxable, 2)
elif int(salary) > 125140:
    tax = 47
    band = "Additional Rate"
    taxable = round((int(salary)/100) * tax, 2)
    keep = round(int(salary) - taxable, 2)
else:
    print("No")

monthly_keeping = int(keep)/12
monthly_keep = round(monthly_keeping, 2)

print(f"""You tax band will be {band}. 
This Means you pay {tax}% in tax. 
You will keep £{keep} out of your £{salary} salary.
This will be a monthly net wage of £{monthly_keep}""")

tax_band_total = tk.Label(text=f"{band}")
taxation_total = tk.Label(text=f"{tax}")
yearly_net_wage_total = tk.Label(text=f"{keep}")
monthly_net_wage_total = tk.Label(text=f"{monthly_keep}")

tax_band_total.grid(column=2, row=3)
taxation_total.grid(column=2, row=4)
yearly_net_wage_total.grid(column=2, row=5)
monthly_net_wage_total.grid(column=2, row=6)

# ------------------------------------------------------------------ #


window.mainloop()

`

What I would like is for a salary to be added to the Entry widget and then it to alter the salary variable to that number when the "Calculate" button is pushed.

Answer 1

You need to move the calculation in the main block into gross_salary() function and update the labels with the result:

import tkinter as tk

window = tk.Tk()

title = tk.Label(window, text="Salary Calculator")
title.grid(column=1, row=0)

canvas = tk.Canvas(window, width=300, height=300, bg="black",)
canvas.grid(column=1, row=1)

gross_wage_title = tk.Label(window, text="Enter gross wage: £")
tax_band_title = tk.Label(window, text="Your Tax band is: ")
taxation_title = tk.Label(window, text="Amount to pay in tax: £")
yearly_net_wage_title = tk.Label(window, text="Your yearly net wage will be: £")
monthly_net_wage_title = tk.Label(window, text="Your monthly net wage will be: £")

gross_wage_title.grid(column=0, row=2, columnspan=2)
tax_band_title.grid(column=0, row=3, columnspan=2)
taxation_title.grid(column=0, row=4, columnspan=2)
yearly_net_wage_title.grid(column=0, row=5, columnspan=2)
monthly_net_wage_title.grid(column=0, row=6, columnspan=2)

def gross_salary():
    global salary
    try:
        salary = int(gross_wage_input.get().strip())

        if salary < 12570:
            tax = 0
            band = "No Rate"
            keep = salary
        elif int(salary) in range(12570, 14732):
            tax = 19
            band = "Starter Rate"
            taxable = round((int(salary)/100) * tax, 2)
            keep = round(int(salary) - taxable, 2)
        elif int(salary) in range(14733, 25688):
            tax = 20
            band = "Basic Rate"
            taxable = round((int(salary)/100) * tax, 2)
            keep = round(int(salary) - taxable, 2)
        elif int(salary) in range(25689, 43662):
            tax = 21
            band = "Intermediate Rate"
            taxable = round((int(salary)/100) * tax, 2)
            keep = round(int(salary) - taxable, 2)
        elif int(salary) in range(43663, 125140):
            tax = 42
            band = "Higher Rate"
            taxable = round((int(salary)/100) * tax, 2)
            keep = round(int(salary) - taxable, 2)
        elif int(salary) > 125140:
            tax = 47
            band = "Additional Rate"
            taxable = round((int(salary)/100) * tax, 2)
            keep = round(int(salary) - taxable, 2)
        else:
            print("No")
            return

        monthly_keeping = int(keep)/12
        monthly_keep = round(monthly_keeping, 2)

        print(f"""You tax band will be {band}.
        This Means you pay {tax}% in tax.
        You will keep £{keep} out of your £{salary} salary.
        This will be a monthly net wage of £{monthly_keep}""")

        # show result
        tax_band_total.config(text=f"{band}")
        taxation_total.config(text=f"{tax}")
        yearly_net_wage_total.config(text=f"{keep}")
        monthly_net_wage_total.config(text=f"{monthly_keep}")

    except ValueError as err:
        print(err)

gross_wage_input = tk.Entry(window)
gross_wage_input.grid(column=2, row=2)

calculate = tk.Button(window, text="Calculate", command=gross_salary)
calculate.grid(column=2, row=7)

tax_band_total = tk.Label(window)
taxation_total = tk.Label(window)
yearly_net_wage_total = tk.Label(window)
monthly_net_wage_total = tk.Label(window)

tax_band_total.grid(column=2, row=3)
taxation_total.grid(column=2, row=4)
yearly_net_wage_total.grid(column=2, row=5)
monthly_net_wage_total.grid(column=2, row=6)

window.mainloop()

Note that it is better to specify the master/parent of the widgets when creating them.

Answer 2

Attempting to make a tax calculator and I have been struggling to work out how to make it so that the variable (salary) can change using an input in an entry box and a button to confirm the entry.

The problem can be fixed by Adding method my_pay(data) and called inside gross_salary() function.

Snippet:

def gross_salary():
    global salary
    salary = (gross_wage_input.get())
    my_pay(salary)

salary = 0
def my_pay(data):
    if salary < '12570':
        tax = 0
        band = "No Rate"
        keep = salary
    elif int(salary) in range(12570, 14732):
        tax = 19
        band = "Starter Rate"
        taxable = round((int(salary)/100) * tax, 2)
        keep = round(int(salary) - taxable, 2)
    elif int(salary) in range(14733, 25688):
        tax = 20
        band = "Basic Rate"
        taxable = round((int(salary)/100) * tax, 2)
        keep = round(int(salary) - taxable, 2)
    elif int(salary) in range(25689, 43662):
        tax = 21
        band = "Intermediate Rate"
        taxable = round((int(salary)/100) * tax, 2)
        keep = round(int(salary) - taxable, 2)
    elif int(salary) in range(43663, 125140):
        tax = 42
        band = "Higher Rate"
        taxable = round((int(salary)/100) * tax, 2)
        keep = round(int(salary) - taxable, 2)
    elif int(salary) > 125140:
        tax = 47
        band = "Additional Rate"
        taxable = round((int(salary)/100) * tax, 2)
        keep = round(int(salary) - taxable, 2)
    else:
        print("No")

    monthly_keeping = int(keep)/12
    monthly_keep = round(monthly_keeping, 2)

    txt = f"""You tax band will be {band}. 
    This Means you pay {tax}% in tax. 
    You will keep £{keep} out of your £{salary} salary.
    This will be a monthly net wage of £{monthly_keep}"""

    canvas.create_text((135, 50), text = txt, fill='orange', font='tkDefaeultFont 8')

    tax_band_total = tk.Label(text=f"{band}")
    taxation_total = tk.Label(text=f"{tax}")
    yearly_net_wage_total = tk.Label(text=f"{keep}")
    monthly_net_wage_total = tk.Label(text=f"{monthly_keep}")

    tax_band_total.grid(column=2, row=3)
    taxation_total.grid(column=2, row=4)
    yearly_net_wage_total.grid(column=2, row=5)
    monthly_net_wage_total.grid(column=2, row=6)

Screenshot: