用python简单代码做一个计算器

#用python简单代码做一个计算器

def create(self):
    """创建界面"""
    btn_list = ["C", "M->", "->M", "/",
                "7", "8", "9", "*",
                "4", "5", "6", "-",
                "1", "2", "3", "+",
                "+/-", "0", ".", "="]
    r = 1
    c = 0
    for b in btn_list:
        self.button = tk.Button(self, text=b, width=5,
                                command=(lambda x=b: self.click(x)))
        self.button.grid(row=r, column=c, padx=3, pady=6)
        c += 1
        if c > 3:
            c = 0
            r += 1
    self.entry = tk.Entry(self, width=24, borderwidth=2,
                          bg="yellow", font=("Consolas", 12))
    self.entry.grid(row=0, column=0, columnspan=4, padx=8, pady=6)

def click(self, key):
    """响应按钮"""
    if key == "=":  # 输出结果
        result = eval(self.entry.get())
        self.entry.insert(tk.END, " = " + str(result))
    elif key == "C":  # 清空输入框
        self.entry.delete(0, tk.END)
    elif key == "->M":  # 存入数值
        self.memory = self.entry.get()
        if "=" in self.memory:
            ix = self.memory.find("=")
            self.memory = self.memory[ix + 2:]
        self.title("M=" + self.memory)
    elif key == "M->":  # 取出数值
        if self.memory:
            self.entry.insert(tk.END, self.memory)
    elif key == "+/-":  # 正负翻转
        if "=" in self.entry.get():
            self.entry.delete(0, tk.END)
        elif self.entry.get()[0] == "-":
            self.entry.delete(0)
        else:
            self.entry.insert(0, "-")
    else:  # 其他键
        if "=" in self.entry.get():
            self.entry.delete(0, tk.END)
        self.entry.insert(tk.END, key)

效果展示：