使用tkinter制作一个简单的计算器，能完成浮点数的加减乘除计算。

好的，以下是一个简单的基于tkinter的计算器代码：

import tkinter as tk

class Calculator(tk.Frame):
    def __init__(self, master=None):
        super().__init__(master)
        self.grid()
        self.create_widgets()
        self.result = 0
        self.current = ""
        self.operator = ""

    def create_widgets(self):
        self.display = tk.Entry(self, width=20, font=("Arial", 16))
        self.display.grid(row=0, column=0, columnspan=4, pady=5)

        self.button_1 = tk.Button(self, text="1", width=5, font=("Arial", 16), command=lambda: self.add_number("1"))
        self.button_1.grid(row=1, column=0, pady=5)

        self.button_2 = tk.Button(self, text="2", width=5, font=("Arial", 16), command=lambda: self.add_number("2"))
        self.button_2.grid(row=1, column=1, pady=5)

        self.button_3 = tk.Button(self, text="3", width=5, font=("Arial", 16), command=lambda: self.add_number("3"))
        self.button_3.grid(row=1, column=2, pady=5)

        self.button_4 = tk.Button(self, text="4", width=5, font=("Arial", 16), command=lambda: self.add_number("4"))
        self.button_4.grid(row=2, column=0, pady=5)

        self.button_5 = tk.Button(self, text="5", width=5, font=("Arial", 16), command=lambda: self.add_number("5"))
        self.button_5.grid(row=2, column=1, pady=5)

        self.button_6 = tk.Button(self, text="6", width=5, font=("Arial", 16), command=lambda: self.add_number("6"))
        self.button_6.grid(row=2, column=2, pady=5)

        self.button_7 = tk.Button(self, text="7", width=5, font=("Arial", 16), command=lambda: self.add_number("7"))
        self.button_7.grid(row=3, column=0, pady=5)

        self.button_8 = tk.Button(self, text="8", width=5, font=("Arial", 16), command=lambda: self.add_number("8"))
        self.button_8.grid(row=3, column=1, pady=5)

        self.button_9 = tk.Button(self, text="9", width=5, font=("Arial", 16), command=lambda: self.add_number("9"))
        self.button_9.grid(row=3, column=2, pady=5)

        self.button_0 = tk.Button(self, text="0", width=5, font=("Arial", 16), command=lambda: self.add_number("0"))
        self.button_0.grid(row=4, column=1, pady=5)

        self.button_plus = tk.Button(self, text="+", width=5, font=("Arial", 16), command=lambda: self.add_operator("+"))
        self.button_plus.grid(row=1, column=3, pady=5)

        self.button_minus = tk.Button(self, text="-", width=5, font=("Arial", 16), command=lambda: self.add_operator("-"))
        self.button_minus.grid(row=2, column=3, pady=5)

        self.button_multiply = tk.Button(self, text="*", width=5, font=("Arial", 16), command=lambda: self.add_operator("*"))
        self.button_multiply.grid(row=3, column=3, pady=5)

        self.button_divide = tk.Button(self, text="/", width=5, font=("Arial", 16), command=lambda: self.add_operator("/"))
        self.button_divide.grid(row=4, column=3, pady=5)

        self.button_clear = tk.Button(self, text="C", width=5, font=("Arial", 16), command=self.clear)
        self.button_clear.grid(row=4, column=0, pady=5)

        self.button_dot = tk.Button(self, text=".", width=5, font=("Arial", 16), command=lambda: self.add_number("."))
        self.button_dot.grid(row=4, column=2, pady=5)

        self.button_equal = tk.Button(self, text="=", width=5, font=("Arial", 16), command=self.calculate)
        self.button_equal.grid(row=5, column=0, columnspan=4, pady=5)

    def add_number(self, number):
        self.current += str(number)
        self.display.delete(0, tk.END)
        self.display.insert(0, self.current)

    def add_operator(self, operator):
        self.operator = operator
        self.result = float(self.current)
        self.current = ""

    def clear(self):
        self.result = 0
        self.current = ""
        self.operator = ""
        self.display.delete(0, tk.END)

    def calculate(self):
        if self.operator == "+":
            self.result += float(self.current)
        elif self.operator == "-":
            self.result -= float(self.current)
        elif self.operator == "*":
            self.result *= float(self.current)
        elif self.operator == "/":
            self.result /= float(self.current)
        self.display.delete(0, tk.END)
        self.display.insert(0, self.result)
        self.current = ""

root = tk.Tk()
calculator = Calculator(root)
calculator.mainloop()

这个计算器使用grid布局，包含数字、运算符、小数点和清除键。`add_number()` 方法将数字添加到当前输入中，`add_operator()` 方法将运算符记录下来并计算当前结果，`calculate()` 方法根据当前运算符计算结果。`clear()` 方法清除所有输入并重置结果和运算符。