我正在用Tkinter构建一个计算器，我的平方根按钮有困难。我收到以下错误：'str' object has no attribute 'sqrt'，我不知道如何解决它。
我将全局变量f_num设置为变量first_number的整数，但显然平方根函数将其识别为str，这对我来说没有意义。
这是我的代码：
from tkinter import *
import math
root = Tk()
root.title("More Complex Calculator")
entry_1 = Entry(root, width = 50, borderwidth = 5)
entry_1.grid(row = 0, column = 0, columnspan = 4, padx = 10, pady = 10)
def button_click(number):
current = entry_1.get()
entry_1.delete(0, END)
entry_1.insert(0,str(current) + str(number))
def button_add():
first_number = entry_1.get()
global f_num
global math
math = "addition"
f_num = int(first_number)
entry_1.delete(0, END)
def button_sub():
first_number = entry_1.get()
global f_num
global math
math = "subtraction"
f_num = int(first_number)
entry_1.delete(0, END)
def button_mult():
first_number = entry_1.get()
global f_num
global math
math = "multiplication"
f_num = int(first_number)
entry_1.delete(0, END)
def button_div():
first_number = entry_1.get()
global f_num
global math
math = "division"
f_num = int(first_number)
entry_1.delete(0, END)
def button_square():
first_number = entry_1.get()
global f_num
global math
math = "square"
f_num = int(first_number)
def button_root():
first_number = entry_1.get()
global f_num
global math
math = "root"
f_num = int(first_number)
def button_enter():
second_number = entry_1.get()
entry_1.delete(0, END)
if math == "addition":
entry_1.insert(0, f_num + int(second_number))
elif math == "subtraction":
entry_1.insert(0, f_num - int(second_number))
elif math == "multiplication":
entry_1.insert(0, f_num * int(second_number))
elif math == "division":
entry_1.insert(0, f_num / int(second_number))
elif math == "square":
entry_1.insert(0, f_num**2)
elif math == "root":
entry_1.insert(0, math.sqrt(f_num))
def button_clear():
entry_1.delete(0, END)
button_0 = Button(root, text = "0", padx = 40, pady = 20, command = lambda: button_click(0))
button_1 = Button(root, text = "1", padx = 40, pady = 20, command = lambda: button_click(1))
button_2 = Button(root, text = "2", padx = 40, pady = 20, command = lambda: button_click(2))
button_3 = Button(root, text = "3", padx = 40, pady = 20, command = lambda: button_click(3))
button_4 = Button(root, text = "4", padx = 40, pady = 20, command = lambda: button_click(4))
button_5 = Button(root, text = "5", padx = 40, pady = 20, command = lambda: button_click(5))
button_6 = Button(root, text = "6", padx = 40, pady = 20, command = lambda: button_click(6))
button_7 = Button(root, text = "7", padx = 40, pady = 20, command = lambda: button_click(7))
button_8 = Button(root, text = "8", padx = 40, pady = 20, command = lambda: button_click(8))
button_9 = Button(root, text = "9", padx = 40, pady = 20, command = lambda: button_click(9))
button_pi = Button(root, text = "π", padx = 39, pady = 20, command = lambda: button_click(math.pi))
button_e = Button(root, text = "e", padx = 40, pady = 20, command = lambda: button_click(math.e))
button_add = Button(root, text = "+", padx = 39, pady = 20, command = button_add)
button_enter = Button(root, text = "=", padx = 39, pady = 20, command = button_enter)
button_clear = Button(root, text = "C", padx = 39, pady = 20, command = button_clear)
button_sub = Button(root, text = "-", padx = 41, pady = 20, command = button_sub)
button_mult = Button(root, text = "x", padx = 40, pady = 20, command = button_mult)
button_div = Button(root, text = "÷", padx = 40, pady = 20, command = button_div)
button_square = Button(root, text = "x²", padx = 38, pady = 20, command = button_square)
button_sqroot = Button(root, text = "√x", padx = 36, pady = 20, command = button_root)
button_1.grid(row = 4, column = 0)
button_2.grid(row = 4, column = 1)
button_3.grid(row = 4, column = 2)
button_4.grid(row = 3, column = 0)
button_5.grid(row = 3, column = 1)
button_6.grid(row = 3, column = 2)
button_7.grid(row = 2, column = 0)
button_8.grid(row = 2, column = 1)
button_9.grid(row = 2, column = 2)
button_0.grid(row = 5, column = 1)
button_square.grid(row = 1, column = 2)
button_sqroot.grid(row = 1, column = 3)
button_add.grid(row = 2, column = 3)
button_enter.grid(row = 5, column = 2)
button_clear.grid(row = 5, column = 0)
button_pi.grid(row = 1, column = 0)
button_e.grid(row = 1, column = 1)
button_sub.grid(row = 3, column = 3)
button_mult.grid(row = 4, column = 3)
button_div.grid(row = 5, column = 3)
root.mainloop()
这是因为您创建了一个名为math的变量，该变量将覆盖您的import math
您正在用字符串覆盖math。例如，在button_add中，您有一行math = "addition"。为该全局变量选择一个不同的名称，您应该可以。例如：
def button_add():
first_number = entry_1.get()
global f_num
global op
op = "addition" # Here!
f_num = int(first_number)
entry_1.delete(0, END)