用tkinter实现一个简单计算器，支持小数点，多次运算

好的，以下是一个简单的计算器演示程序：

from tkinter import *

class Calculator:
    def __init__(self, master):
        self.master = master
        master.title("简单计算器")

        self.screen = Text(master, state='disabled', width=30, height=3,background="white", foreground="blue")
        self.screen.grid(row=0,column=0,columnspan=4,padx=5,pady=5)

        self.equation = ''

        # 创建按钮
        b1 = self.create_button(7)
        b2 = self.create_button(8)
        b3 = self.create_button(9)
        b4 = self.create_button(u"\u232B", None)
        b5 = self.create_button(4)
        b6 = self.create_button(5)
        b7 = self.create_button(6)
        b8 = self.create_button(u"\u00F7")
        b9 = self.create_button(1)
        b10 = self.create_button(2)
        b11 = self.create_button(3)
        b12 = self.create_button('*')
        b13 = self.create_button('.')
        b14 = self.create_button(0)
        b15 = self.create_button('+')
        b16 = self.create_button('-')
        b17 = self.create_button('=', None, 34)

        # 将按钮添加到列表中
        buttons = [b1, b2, b3, b4, b5, b6, b7, b8, b9, b10, b11, b12, b13, b14, b15, b16, b17]

        # 将按钮添加到网格中
        count = 0
        for row in range(1, 5):
            for column in range(4):
                buttons[count].grid(row=row, column=column)
                count += 1
        buttons[16].grid(row=5, column=0, columnspan=4)

    def create_button(self, val, write=True, width=7):
        return Button(self.master, text=val, command=lambda:self.click(val,write), width=width, height=2, bg="white", fg="black")

    def click(self, text, write):
        if write == None:
            if text == '=' and self.equation:
                try:
                    result = str(eval(self.equation))
                    self.clear_screen()
                    self.insert_screen(result, newline=True)
                except:
                    self.clear_screen()
                    self.insert_screen("Error!", newline=True)
            elif text == u"\u232B":
                self.clear_screen()
        else:
            self.insert_screen(text)

    def clear_screen(self):
        self.equation = ''
        self.screen.configure(state='normal')
        self.screen.delete('1.0', END)

    def insert_screen(self, value, newline=False):
        self.screen.configure(state='normal')
        self.screen.insert(END, value)
        self.equation += str(value)
        self.screen.configure(state='disabled')

root = Tk()
gui = Calculator(root)
root.mainloop()

这个程序使用了Tkinter库来创建一个简单的计算器界面，支持小数点和多次运算。你可以按照自己的需要进行修改和扩展。