我有一个可以进行指数计算的计算器程序，但它不喜欢（不能处理）像10 ^ 10000000000000这样的东西。我看到上一篇文章说使用信号超时，但那只是unix。关于我的代码的另一点：当按下equals时，它通过try块运行输入，异常将ERROR打印到计算器的显示。有什么办法可以检测到潜在的溢出并在经过一段时间后引发错误或超时（引发错误）？注意：文件需要转移到另一个系统，因此解决方案必须是通用的。谢谢！ 编辑：我使用python运行tkinter来制作下面的GUI。我需要将文件传输到运行Jessie的raspberry pi。
from tkinter import *
import math
class Calc:
def __init__(self,master):
self.master = master
self.lastbutton = ''
self.varlist = dict()
self.varlist = {"A":"0","B":"0","C":"0","D":"0","E":"0","F":"0","G":"0","H":"0","I":"0","J":"0"}
self.dlist = dict()
self.dlist = {'^':'**','sqrt(':'math.sqrt(',')cubrt':'**(1/3)',
'sin(':'math.sin(','cos(':'math.cos(','tan(':'math.tan(',
'arcsin(':'math.asin(','arccos(':'math.acos(','arctan(':'math.atan(',"τ":"(math.tau)",
'π':'(math.pi)','e':'(math.e)',"e^":"math.exp(",'(π/2)':'((math.pi)/2)','(π/3)':'((math.pi)/3)','(π/4)':'((math.pi)/4)',
"A":"self.varlist['A']","B":"self.varlist['B']","C":"self.varlist['C']","D":"self.varlist['D']",
"E":"self.varlist['E']","F":"self.varlist['F']","G":"self.varlist['G']","H":"self.varlist['H']",
"I":"self.varlist['I']","J":"self.varlist['J']",
"mod(":"math.fmod(","e^(":"math.exp(","ln(":"math.log(","log(":"math.log10(","log b (":"math.log(",
"sec(":"(1/math.cos(","csc(":"(1/math.sin(","cot(":"(1/math.tan(","arcsec(":"(1/math.acos(","arccsc(":"(1/math.asin(","arccot(":"(1/math.atan(",
"toRadians(":"math.radians(","toDegrees":"math.degrees(","hypot(":"math.hypot("}
self.text1 = StringVar(value = '1')
self.text2 = StringVar(value = '2')
self.text3 = StringVar(value = '3')
self.text4 = StringVar(value = '4')
self.text5 = StringVar(value = '5')
self.text6 = StringVar(value = '6')
self.text7 = StringVar(value = '7')
self.text8 = StringVar(value = '8')
self.text9 = StringVar(value = '9')
self.text0 = StringVar(value = '0')
self.acl = StringVar(value = 'Del')
self.period = StringVar(value = '.')
self.shft = StringVar(value = 'shft1')
self.var1 = StringVar()
self.var2 = StringVar()
self.var3 = StringVar()
self.option1 = ['^2','^3','sqrt(',')cubrt','^','mod(','ln(','log(','log b (']
self.option2 = ['τ','π','e','e^','(π/2)','(π/3)','(π/4)','toRadians(','toDegrees(']
self.option3 = ['sin(','cos(','tan(','arcsin(','arccos(','arctan(', 'sec(', 'csc(','cot(','arcsec(','arccsc(','arccot(','hypot(']
self.master.title('My Calculator')
self.displaya = Entry(master)
self.displaya.grid(row = 0, columnspan = 6)
self.displayb = Entry(master)
self.displayb.grid(row = 1, columnspan = 6)
self.displayc = Entry(master)
self.displayc.grid(row = 2, columnspan = 6)
self.one = Button(master, textvariable = self.text1,width = 10, command = lambda: self.display(self.text1.get()))
self.one.grid(row = 4, column = 0)
self.two = Button(master, textvariable = self.text2,width = 10, command = lambda: self.display(self.text2.get()))
self.two.grid(row = 4, column = 1)
self.three = Button(master, textvariable = self.text3, width = 10,command = lambda: self.display(self.text3.get()))
self.three.grid(row = 4, column = 2)
self.four = Button(master, textvariable = self.text4, width = 10,command = lambda: self.display(self.text4.get()))
self.four.grid(row = 5, column = 0)
self.five = Button(master, textvariable = self.text5,width = 10, command = lambda: self.display(self.text5.get()))
self.five.grid(row = 5, column = 1)
self.six = Button(master, textvariable = self.text6,width = 10, command = lambda: self.display(self.text6.get()))
self.six.grid(row = 5, column = 2)
self.seven = Button(master, textvariable = self.text7,width = 10, command = lambda: self.display(self.text7.get()))
self.seven.grid(row = 6, column = 0)
self.eight = Button(master, textvariable = self.text8, width = 10,command = lambda: self.display(self.text8.get()))
self.eight.grid(row = 6, column = 1)
self.nine = Button(master, textvariable = self.text9, width = 10,command = lambda: self.display(self.text9.get()))
self.nine.grid(row = 6, column = 2)
self.zero = Button(master, textvariable = self.text0, width = 10,command = lambda: self.display(self.text0.get()))
self.zero.grid(row = 7, column = 1)
self.result = Button(master, text = '=', width = 10, height = 1, command = lambda : self.equals())
self.result.grid(row = 7, column = 0)
self.ac = Button(master, textvariable = self.acl, width = 10, height = 1, command = lambda : self.clear(self.acl.get()))
self.ac.grid(row = 7, column = 2)
self.plus = Button(master, text = '+', width = 10, height = 1, command = lambda : self.display('+'))
self.plus.grid(row = 4, column = 3)
self.minus = Button(master, text = '-', width = 10, height = 1, command = lambda : self.display('-'))
self.minus.grid(row = 5, column = 3)
self.times = Button(master, text = '*', width = 10, height = 1, command = lambda : self.display('*'))
self.times.grid(row = 6, column = 3)
self.div = Button(master, text = '/', width = 10, height = 1, command = lambda : self.display('/'))
self.div.grid(row = 7, column = 3)
self.per = Button(master, textvariable = self.period, width = 4, command = lambda : self.display(self.period.get()))
self.per.grid(row = 1, column = 0)
self.opp = Button(master, text = '(', width = 1, height = 1, command = lambda : self.display('('))
self.opp.grid(row = 0, column = 1)
self.clp = Button(master, text = ')', width = 1, height = 1, command = lambda : self.display(')'))
self.clp.grid(row = 1, column = 1)
self.update_button = Button(master, textvariable = self.shft, width = 4, command = lambda: self.update(int(self.shft.get()[4:5])))
self.update_button.grid(row = 0, column = 0)
self.store = Button(master, text = 'sto', command = lambda : self.sto(self.displayc.get()))
self.store.grid(row = 2, column = 1)
self.menu1 = OptionMenu(master, self.var1, *self.option1)
self.menu1.grid(row = 4, column = 4, ipadx = 20)
self.menu2 = OptionMenu(master, self.var2, *self.option2)
self.menu2.grid(row = 5, column = 4, ipadx = 20)
self.menu3 = OptionMenu(master, self.var3, *self.option3)
self.menu3.grid(row = 6, column = 4, ipadx = 20)
self.place1 = Button(root, text = 'Place', width = 10, height = 1, command = lambda : self.display(self.var1.get()))
self.place1.grid(row = 4, column = 5)
self.place2 = Button(root, text = 'Place', width = 10, height = 1, command = lambda : self.display(self.var2.get()))
self.place2.grid(row = 5, column = 5)
self.place3 = Button(root, text = 'Place', width = 10, height = 1, command = lambda : self.display(self.var3.get()))
self.place3.grid(row = 6, column = 5)
self.hbox = Text(master, height = 5, width = 35)
self.hbox.grid(row = 1, rowspan = 3, column = 4, columnspan = 2)
self.help = Button(master, text = 'Help', command = lambda : self.hlp())
self.help.grid(row = 2, column = 0)
def update(self, mode):
if mode == 1:
self.text1.set('A')
self.text2.set('B')
self.text3.set('C')
self.text4.set('D')
self.text5.set('E')
self.text6.set('F')
self.text7.set('G')
self.text8.set('H')
self.text9.set('I')
self.text0.set('J')
self.acl.set('AC')
self.period.set(',')
self.shft.set('shft2')
else:
self.text1.set('1')
self.text2.set('2')
self.text3.set('3')
self.text4.set('4')
self.text5.set('5')
self.text6.set('6')
self.text7.set('7')
self.text8.set('8')
self.text9.set('9')
self.text0.set('0')
self.acl.set('Del')
self.period.set('.')
self.shft.set('shft1')
def sto(self, dis):
disl = dis.split(',')
var = disl[0]
val = disl[1]
self.varlist[var] = val
self.displaya.delete(0,END)
self.displaya.insert(0, self.displayb.get())
self.displayb.delete(0,END)
txt = val + '-->' + var
self.displayb.insert(0, txt)
self.displayc.delete(0,END)
self.displayc.insert(0, round(float(val), 7))
self.lastbutton = 'sto('
def hlp(self):
self.hbox.delete(1.0, END)
sme = dict()
sme = {"-":"+","*":"+","/":"+","B":"A","C":"A","D":"A","E":"A","F":"A","G":"A","H":"A","I":"A","J":"A",
"cos(":"sin(","tan(":"sin(","arcsin(":"sin(","arccos(":"sin(","arctan(":"sin(",
"sec(":"sin(","csc(":"sin(","cot(":"sin(","arcsec(":"sin(","arccsc(":"sin(","arccot(":"sin("}
bh = dict()
bh = {"+":"+, -, *, / \n Arithmetic operators (op)\n format : x op y",
"sin(":"sin(), cos(), etc\n Trigonometric functions (funct()) \nformat : funct(x)",
"A":"Variables can hold 1 value\nat a time with STO\nuse like number",
"^2":"Square (exponent = 2)\n format : x^2",
"^":"Carrot (x ^ y)\n format : x^y",
")cubrt":"Cube root\n format : (x)cubrt",
"sqrt(":"Square root\n format : sqrt(x)",
"mod(":"Modulo (remainder x/y)\nformat : mod(x,y)",
"ln(":"Natural log\n format : ln(x)",
"log(":"Log base 10\n format : log(x)",
"log b (":"Logarithm of base b\n format : log(x,b)",
"sto(":"Store value to variable\n format : sto(variable,value)",
"hypot(":"Hypotenuse (Pythagorean theorem)\n Find hypotenuse given two sides\n format : hypot(s1,s2)"}
helpfunct = sme[self.lastbutton] if self.lastbutton in sme.keys() else self.lastbutton
new = bh[helpfunct] if helpfunct in bh.keys() else "No help available for this item"
add = 'Help:' + '\n' + new
self.hbox.insert(1.0, add)
def display(self,e):
self.displayc.insert(END,e)
self.lastbutton = e
def equals(self):
self.displaya.delete(0,END)
b = self.displayb.get()
self.displaya.insert(0, b)
self.displayb.delete(0,END)
c = self.displayc.get()
for key in self.dlist:
c = c.replace(key, self.dlist[key])
try:
equals = round(float(eval(c)),7)
c = c + '=' + str(equals)
self.displayb.insert(0, c)
self.displayc.delete(0,END)
self.displayc.insert(0, equals)
except ZeroDivisionError:
self.displayb.insert(0,c)
c = 'Error: Div by Zero: '
self.displayc.insert(0,c)
except SyntaxError:
self.displayb.insert(0,c)
c = 'Error: Syntax'
self.displayc.delete(0,END)
self.displayc.insert(0,c)
except IndexError:
self.displayb.insert(0,c)
c = 'Error: Syntax'
self.displayc.delete(0,END)
self.displayc.insert(0,c)
except TypeError:
self.displayb.insert(0,c)
c = 'Error: Syntax'
self.displayc.delete(0,END)
self.displayc.insert(0,c)
return
def clear(self, com):
if com == 'AC':
if len(self.displayc.get()) == 0:
self.displayb.delete(0, END)
self.displaya.delete(0, END)
else:
self.displayc.delete(0, END)
else:
self.displayc.delete(len(self.displayc.get())-1,END)
return
root = Tk()
calc = Calc(root)
root.mainloop()
答案 0 :(得分：0)
你的特殊问题是表达式10^10000000000000（你翻译成10**10000000000000只包含整数，Python支持任意精度整数，所以它试图给你一个答案......
但是从您的代码中可以清楚地看到您正在编写浮点计算器。如果将表达式更改为10.0**10000000000000.0，则会出现即时溢出异常，请添加try:except:，然后您可以捕获并显示合适的结果。
您需要弄清楚如何在代码中添加.0。您还应该考虑如果您的用户输入了3+*4或其他垃圾，会发生什么。问问自己，使用eval是否真的是实现计算器的最佳方式。
HTH