python编写计算器，供大家参考，具体内容如下
（1）计算器界面如下：
（2）基本满足了计算器的所有需求，使用时不可键盘输入，只能鼠标点击左键才可执行。初始时显示0.0，每次输入的内容存于D:\\num.txt(启动程序时自动创建)
（3）\” AC \” 记录清零返回初始 0.0；\” delete \” 删除上一个输入内容；\” +/- \” 将正数为负数，负数为正数
（4）对于不同的进制数值系统，小数的精准值不同。
因此计算机会出现 0.1+0.2=0.3000000000004 的现象
能对数据进行截断处理，可以解决问题，但精度丧失。
（此计算机没有进行截断处理）
import tkinter,os
from tkinter import *
def temp(string):#空白间隔
temp=tkinter.Frame(string,width=20,height=50)
temp.pack()
flag=0
node=0
def num_work(): #更新显示框Lable
global flag
global node
with open(\"D:\\\\num.txt\") as f:
for length in f:
string=length
top_work.configure(text=string.strip(\'\\n\')) # 重新设置标签文本
root.after(500,num_work) # 每隔0.5s调用函数num_work自身获取结果
def num_math_int(num1,num2):#整数运算
try:
if num2[0]==\'+\':
string=int(num1)+int(num2[1:])
elif num2[0]==\'-\':
string=int(num1)-int(num2[1:])
elif num2[0]==\'x\':
string=int(num1)*int(num2[1:])
elif num2[0]==\'/\':
string=int(num1)/int(num2[1:])
with open(\"D:\\\\num.txt\",\'a\') as f:
f.write(\'\\n\'+str(string)+\'\\n\')
except:
with open(\"D:\\\\num.txt\",\'a\') as f:
f.write(\'\\n错误\')
def num_math_float(num1,num2):#小数运算
try:
if num2[0]==\'+\':
string=float(num1)+float(num2[1:])
elif num2[0]==\'-\':
string=float(num1)-float(num2[1:])
elif num2[0]==\'x\':
string=float(num1)*float(num2[1:])
elif num2[0]==\'/\':
string=float(num1)/float(num2[1:])
if flag==0:
with open(\"D:\\\\num.txt\",\'a\') as f:
f.write(\'\\n\'+str(string)+\'\\n\')
else:
with open(\"D:\\\\num.txt\",\'a\') as f:
f.write(\'\\n\'+str(string))
except:
with open(\"D:\\\\num.txt\",\'a\') as f:
f.write(\'\\n错误\')
def decimal(num):
if num.count(\'%\')>0:
num=num.replace(\'%\',\'\')
num=num.replace(\'\\n\',\'\')
if num.isnumeric():
num=str(float(num)/100)
else:
num=num[0]+str(float(num[1:])/100)
return num
def work(string):#按键对应的功能
if string.isnumeric():
with open(\"D:\\\\num.txt\",\"a\") as file:
file.write(string)
else:
#读取文件D:\\\\num.txt所有内容
lists=[]
with open(\"D:\\\\num.txt\",\"r\") as file:
for length in file:
lists.append(length)
if string==\'AC\':
with open(\"D:\\\\num.txt\",\"w\") as file:
file.write(\'0.0\\n\')
elif string==\'=\':
num1=lists[-2]
num2=lists[-1]
if num1==\'\\n\':#解决末尾为换行的情况
num1=lists[-3]
#将百分数小数化
#出现结果多0.0000000001
num1=decimal(num1)
num2=decimal(num2)
try: #判断两个数是整数还是小数
number=int(num1)
number=int(num2[1:])
num_math_int(num1,num2)#两个数进行整数运算
except:
num_math_float(num1,num2)#两个数进行小数运算
elif string==\'.\':
if lists[-1].count(\'.\')==0:#判断结尾是否有小数点，没有写入否则报错
with open(\"D:\\\\num.txt\",\"a\") as file:
file.write(string)
else:
with open(\"D:\\\\num.txt\",\"a\") as file:
file.write(\'\\n错误\')
elif string==\'+/-\':
if lists[-1].count(\'-\')==0:#-+为-
if lists[-1].count(\'+\')==1:
lists[-1]=lists[-1].replace(\'+\',\'\')
lists[-1]=\'-\'+lists[-1]
else: #--为+
lists[-1]=lists[-1].replace(\'-\',\'+\')
#更新文件
with open(\"D:\\\\num.txt\",\"w\") as file:
pass
for length in lists:
with open(\"D:\\\\num.txt\",\"a\") as file:
file.write(length)
elif string==\'delete\':
number=lists[-1]
lists[-1]=number[0:(len(number)-1)]#删除一位
#更新文件
with open(\"D:\\\\num.txt\",\"w\") as file:
pass
for length in lists:
with open(\"D:\\\\num.txt\",\"a\") as file:
file.write(length)
elif string==\'%\':
if lists[-1].endswith(\"%\")==False:
with open(\"D:\\\\num.txt\",\"a\") as file:
file.write(string)
else:
with open(\"D:\\\\num.txt\",\"a\") as file:
file.write(\'\\n错误\')
else:
with open(\"D:\\\\num.txt\",\"a\") as file:
file.write(\'\\n\'+string)
def run():#计算器显示界面主体
if os.path.exists(\"D:\\\\num.txt\")==False:
with open(\"D:\\\\num.txt\",\'w\') as f:
f.write(\'0.0\\n\')
global root#定义全局变量root,方便Label更新
root=tkinter.Tk()
root.title(\"计算器\")
#x = root.winfo_screenwidth()
#获取当前屏幕的宽
#y = root.winfo_screenheight()
#获取当前屏幕的高
#print(((x-500)//2),((y-600)//2))#为居中提供的参数
root.geometry(\'400x500+760+290\')#主体长400，高500，居中
top=tkinter.Frame(root,width=20,height=50)
top.pack()
global top_work#定义全局变量root
temp(top)#空白间隔
#计算器显示框
top_work=tkinter.Label(top,text=\'\',justify=\'left\',relief=SUNKEN,bd=10,bg=\'white\',width=40)
top_work.pack(side=\'bottom\')#计算器显示框（位置居下）
num_work()
temp(root)#空白间隔
number=tkinter.Frame(root)#成放计算机键盘的容器
number.pack()
#所有按键，AC键为事例
numberAC=tkinter.Button(number,text=\"AC\",width=10,command=lambda : work(\'AC\')).grid(row=0,column=0)
#左键点击，执行函数work
#按键位置（0,0）
numberdelete=tkinter.Button(number,text=\"delete\",width=10,command=lambda : work(\'delete\')).grid(row=0,column=1)
numberzhengfu=tkinter.Button(number,text=\"+/-\",width=10,command=lambda : work(\'+/-\')).grid(row=0,column=2)
numberchu=tkinter.Button(number,text=\"/\",width=10,command=lambda : work(\'/\')).grid(row=0,column=3)
tkinter.Button(number,text=\"7\",width=10,command=lambda : work(\'7\')).grid(row=1,column=0)
tkinter.Button(number,text=\"8\",width=10,command=lambda : work(\'8\')).grid(row=1,column=1)
tkinter.Button(number,text=\"9\",width=10,command=lambda : work(\'9\')).grid(row=1,column=2)
tkinter.Button(number,text=\"x\",width=10,command=lambda : work(\'x\')).grid(row=1,column=3)
tkinter.Button(number,text=\"4\",width=10,command=lambda : work(\'4\')).grid(row=2,column=0)
tkinter.Button(number,text=\"5\",width=10,command=lambda : work(\'5\')).grid(row=2,column=1)
tkinter.Button(number,text=\"6\",width=10,command=lambda : work(\'6\')).grid(row=2,column=2)
tkinter.Button(number,text=\"-\",width=10,command=lambda : work(\'-\')).grid(row=2,column=3)
tkinter.Button(number,text=\"1\",width=10,command=lambda : work(\'1\')).grid(row=3,column=0)
tkinter.Button(number,text=\"2\",width=10,command=lambda : work(\'2\')).grid(row=3,column=1)
tkinter.Button(number,text=\"3\",width=10,command=lambda : work(\'3\')).grid(row=3,column=2)
tkinter.Button(number,text=\"+\",width=10,command=lambda : work(\'+\')).grid(row=3,column=3)
tkinter.Button(number,text=\"%\",width=10,command=lambda : work(\'%\')).grid(row=4,column=0)
tkinter.Button(number,text=\"0\",width=10,command=lambda : work(\'0\')).grid(row=4,column=1)
tkinter.Button(number,text=\".\",width=10,command=lambda : work(\'.\')).grid(row=4,column=2)
tkinter.Button(number,text=\"=\",width=10,command=lambda : work(\'=\')).grid(row=4,column=3)
root.mainloop()
if __name__==\'__main__\':
run()
以上就是本文的全部内容，希望对大家的学习有所帮助，也希望大家多多支持自学编程网。
