assistant: Aquí el ejemplo de calculadora científica:
`cientifica.py`
```py
from tkinter import *
import math
import tkinter.messagebox
  
root = Tk()
root.title("Scientific Calculator")
root.configure(background="white")
root.resizable(width=False, height=False)
root.geometry("480x568+450+90")
calc = Frame(root)
calc.grid()

class Calc():
    def __init__(self):
        self.total = 0
        self.current = ""
        self.input_value = True
        self.check_sum = False
        self.op = ""
        self.result = False
  
    def number_enter(self, num):
        self.result = False
        firstnum = txtDisplay.get()
        secondnum = str(num)
        if self.input_value:
            self.current = secondnum
            self.input_value = False
        else:
            if secondnum == ".":
                if secondnum in firstnum:
                    return
            self.current = firstnum + secondnum
        self.display(self.current)
  
    def sum_of_total(self):
        self.result = True
        self.current = float(self.current)
        if self.check_sum == True:
            self.valid_function()
        else:
            self.total = float(txtDisplay.get())
  
    def display(self, value):
        txtDisplay.delete(0, END)
        txtDisplay.insert(0, value)
  
    def valid_function(self):
        if self.op == "add":
            self.total += self.current
        if self.op == "sub":
            self.total -= self.current
        if self.op == "multi":
            self.total *= self.current
        if self.op == "divide":
            self.total /= self.current
        if self.op == "mod":
            self.total %= self.current
        self.input_value = True
        self.check_sum = False
        self.display(self.total)
  
    def operation(self, op):
        self.current = float(self.current)
        if self.check_sum:
            self.valid_function()
        elif not self.result:
            self.total = self.current
            self.input_value = True
        self.check_sum = True
        self.op = op
        self.result = False
  
    def clear_entry(self):
        self.result = False
        self.current = "0"
        self.display(0)
        self.input_value = True
  
    def all_clear_entry(self):
        self.clear_entry()
        self.total = 0
  
    def pi(self):
        self.result = False
        self.current = math.pi
        self.display(self.current)
  
    def tau(self):
        self.result = False
        self.current = math.tau
        self.display(self.current)
  
    def e(self):
        self.result = False
        self.current = math.e
        self.display(self.current)
  
    def mathPM(self):
        self.result = False
        self.current = -(float(txtDisplay.get()))
        self.display(self.current)
  
    def squared(self):
        self.result = False
        self.current = math.sqrt(float(txtDisplay.get()))
        self.display(self.current)
  
    def cos(self):
        self.result = False
        self.current = math.cos(math.radians(float(txtDisplay.get())))
        self.display(self.current)
  
    def cosh(self):
        self.result = False
        self.current = math.cosh(math.radians(float(txtDisplay.get())))
        self.display(self.current)
  
    def tan(self):
        self.result = False
        self.current = math.tan(math.radians(float(txtDisplay.get())))
        self.display(self.current)
  
    def tanh(self):
        self.result = False
        self.current = math.tanh(math.radians(float(txtDisplay.get())))
        self.display(self.current)
  
    def sin(self):
        self.result = False
        self.current = math.sin(math.radians(float(txtDisplay.get())))
        self.display(self.current)
  
    def sinh(self):
        self.result = False
        self.current = math.sinh(math.radians(float(txtDisplay.get())))
        self.display(self.current)
  
    def log(self):
        self.result = False
        self.current = math.log(float(txtDisplay.get()))
        self.display(self.current)
  
    def exp(self):
        self.result = False
        self.current = math.exp(float(txtDisplay.get()))
        self.display(self.current)
  
    def acosh(self):
        self.result = False
        self.current = math.acosh(float(txtDisplay.get()))
        self.display(self.current)
  
    def asinh(self):
        self.result = False
        self.current = math.asinh(float(txtDisplay.get()))
        self.display(self.current)
  
    def expm1(self):
        self.result = False
        self.current = math.expm1(float(txtDisplay.get()))
        self.display(self.current)
  
    def lgamma(self):
        self.result = False
        self.current = math.lgamma(float(txtDisplay.get()))
        self.display(self.current)
  
    def degrees(self):
        self.result = False
        self.current = math.degrees(float(txtDisplay.get()))
        self.display(self.current)
  
    def log2(self):
        self.result = False
        self.current = math.log2(float(txtDisplay.get()))
        self.display(self.current)
  
    def log10(self):
        self.result = False
        self.current = math.log10(float(txtDisplay.get()))
        self.display(self.current)
  
    def log1p(self):
        self.result = False
        self.current = math.log1p(float(txtDisplay.get()))
        self.display(self.current)

added_value = Calc()
  
txtDisplay = Entry(calc, font=("Helvetica", 20, "bold"), bg="black", fg="white", bd=30, width=28, justify=RIGHT)
txtDisplay.grid(row=0, column=0, columnspan=4, pady=1)
txtDisplay.insert(0, "0")
  
numberpad = "789456123"
i = 0
btn = []
for j in range(2, 5):
    for k in range(3):
        btn.append(Button(calc, width=6, height=2, bg="black", fg="white", font=("Helvetica", 20, "bold"), bd=4, text=numberpad[i]))
        btn[i].grid(row=j, column=k, pady=1)
        btn[i]["command"] = lambda x = numberpad[i]: added_value.number_enter(x)
        i += 1

btnClear = Button(calc, text=chr(67), width=6, height=2, bg="powder blue", font=("Helvetica", 20, "bold"), bd=4, command=added_value.clear_entry).grid(row=1, column=0, pady=1)
btnAllClear = Button(calc, text=chr(67) + chr(69), width=6, height=2, bg="powder blue", font=("Helvetica", 20, "bold"), bd=4, command=added_value.all_clear_entry).grid(row=1, column=1, pady=1)
btnsq = Button(calc, text="\u221A", width=6, height=2, bg="powder blue", font=("Helvetica", 20, "bold"), bd=4, command=added_value.squared).grid(row=1, column=2, pady=1)
btnAdd = Button(calc, text="+", width=6, height=2, bg="powder blue", font=("Helvetica", 20, "bold"), bd=4, command=lambda:added_value.operation("add")).grid(row=1, column=3, pady=1)
btnSub = Button(calc, text="-", width=6, height=2, bg="powder blue", font=("Helvetica", 20, "bold"), bd=4, command=lambda:added_value.operation("sub")).grid(row=2, column=3, pady=1)
btnMul = Button(calc, text="x", width=6, height=2, bg="powder blue", font=("Helvetica", 20, "bold"), bd=4, command=lambda:added_value.operation("multi")).grid(row=3, column=3, pady=1)
btnDiv = Button(calc, text="/", width=6, height=2, bg="powder blue", font=("Helvetica", 20, "bold"), bd=4, command=lambda:added_value.operation("divide")).grid(row=4, column=3, pady=1)
btnZero = Button(calc, text="0", width=6, height=2, bg="black", fg="white", font=("Helvetica", 20, "bold"), bd=4, command=lambda:added_value.number_enter(0)).grid(row=5, column=0, pady=1)
btnDot = Button(calc, text=".", width=6, height=2, bg="powder blue", font=("Helvetica", 20, "bold"), bd=4, command=lambda:added_value.number_enter(".")).grid(row=5, column=1, pady=1)
btnPM = Button(calc, text=chr(177), width=6, height=2, bg="powder blue", font=("Helvetica", 20, "bold"), bd=4, command=added_value.mathPM).grid(row=5, column=2, pady=1)
btnEquals = Button(calc, text="=", width=6, height=2, bg="powder blue", font=("Helvetica", 20, "bold"), bd=4, command=added_value.sum_of_total).grid(row=5, column=3, pady=1)
# ...
```