Tkinter Calculator

[menator01]

Tried my luck with a simple calculator. As always I welcome feedback.
Esc key will clear. numpad keys work, and enter keys to get totals

#! /usr/bin/env python3

import tkinter as tk
from functools import partial
import decimal

class Calculator:
    def __init__(self, parent):
        self.parent = parent
        self.parent.rowconfigure(0, weight=1)
        self.parent.columnconfigure(0, weight=1)

        # Mainframe
        mainframe = tk.Frame(self.parent)
        mainframe.grid(column=0, row=0, sticky='news')
        mainframe.grid_columnconfigure(0, weight=3)
        mainframe.grid_rowconfigure(0, weight=3)

        buttonframe = tk.Frame(mainframe)
        buttonframe.grid(column=0, row=1, sticky='new')
        buttonframe.grid_columnconfigure(0, weight=3)

        textframe = tk.Frame(mainframe, padx=3, pady=3, borderwidth=3, relief='groove')
        textframe.grid(column=0, row=0, sticky='new')
        textframe.grid_columnconfigure(0, weight=3)

        self.valid = self.parent.register(self.valid_input)
        self.entry = tk.Entry(textframe)
        self.entry.configure(validate='key', validatecommand=(self.valid, '%S'))
        self.entry['font'] = 'sans 14 normal'
        self.entry['relief'] = 'sunken'
        self.entry.focus()
        self.entry.grid(column=0, row=0, sticky='new')

        # Do the buttons
        numbers = [7,8,9,4,5,6,1,2,3,0]
        self.symbols = ['=', '*', '/', '+', '-', '.']

        i = 0
        j=0
        for number in numbers:
            btn = tk.Button(buttonframe, text=number, command=partial(self.press, number), padx=35, pady=5)
            btn['font'] = 'sans 14 normal'
            btn.grid(column=i, row=j, sticky='news')
            if i >= 2:
                i = 0
                j += 1
            else:
                i += 1

        btn = tk.Button(buttonframe, text=self.symbols[5], padx=35, pady=5, command=partial(self.press, self.symbols[5]))
        btn['font'] = 'sans 14 normal'
        btn.grid(column=1, row=3, sticky='news')

        btn = tk.Button(buttonframe, text=self.symbols[0], padx=35, pady=5, command=partial(self.calculations, None))
        btn['font'] = 'sans 14 normal'
        btn.grid(column=2, row=3, sticky='news')

        i = 0
        for symbol in self.symbols:
            if symbol != self.symbols[5]  and symbol != '=':
                btn = tk.Button(buttonframe, text=symbol, padx=35, pady=5, command=partial(self.press, symbol))
                btn['font'] = 'sans 14 normal'
                btn.grid(column=3, row=i, sticky='news')
                i += 1
        btn = tk.Button(buttonframe, text='Clear', fg='red', command=partial(self.clear, None))
        btn['font'] = 'sans 14'
        btn.grid(columnspan=4, column=0, row=5, sticky='news')

        self.parent.bind('<Return>', partial(self.calculations))
        self.parent.bind('<KP_Enter>', partial(self.calculations))
        self.parent.bind('<Escape>', partial(self.clear))


    def clear(self, event):
        self.entry.delete(0, tk.END)

    def valid_input(self,num):
        if num.isalpha() or num == '=':
            return False
        else:
            return True

    def press(self, num):
        self.entry.insert(tk.END, num)

    def calculations(self, event):
        values = self.entry.get()
        self.entry.delete(0, tk.END)
        result = eval(values)
        if isinstance(result, float):
            result = decimal.Decimal(result).normalize()
        else:
            result = result
        self.entry.insert(tk.END, result)

def main():
    root = tk.Tk()
    root.title('Calculator')
    root.configure(borderwidth=5, relief='ridge', padx=3, pady=3)
    Calculator(root)
    root.mainloop()

if __name__ == '__main__':
    main()

[GOTO10]

The interface looks great (on Windows 10), nice and clean. I accidentally caused a syntax error on my first entry because I fat-fingered a key and added an extra decimal point by mistake. This is the first time I've seen partial used, so I had to read up on it to understand how you are using it here.

Great job!

[menator01]

I use partial to pass variables