这篇文章主要介绍了python实现的计算器功能,涉及python四则运算、取反、百分比等相关数学运算操作实现技巧,需要的朋友可以参考下
本文实例讲述了Python实现的计算器功能。分享给大家供大家参考，具体如下：
源码：
# -*- coding:utf-8 -*-
#! python2
from tkinter import *
__author__ = 'tianshl'
__date__ = '2017/10/16'
class Application(Frame):
def __init__(self):
Frame.__init__(self)
self.grid()
self.mem = '' # 内存中的数据
self.opt = '' # 操作符
self.display = StringVar() # 显示的数据
self.display.set('0') # 初始值
self.need_cls = False # 是否需要清屏
self.create_widgets()
# 清空
def clear(self):
self.mem = ''
self.display.set('0')
# 取反
def negative(self):
self.display.set(eval('-' + self.display.get()))
# 四则运算
def option(self, opt):
if not self.need_cls:
self.calculate()
self.opt = opt
self.need_cls = True
self.mem = self.display.get()
# 计算结果
def calculate(self):
if self.opt:
try:
self.display.set(eval(self.mem + self.opt + self.display.get()))
except Exception:
self.display.set('错误')
self.need_cls = True
self.opt = ''
self.mem = ''
# 百分比
def percent(self):
base = float(self.mem or 1) / 100
display = eval('{}*{}'.format(self.display.get(), base))
int_display = int(display)
display = int_display if display == int_display else display
self.display.set(display)
self.need_cls = True
# 输入
def input(self, key):
if self.need_cls:
self.display.set('0')
self.need_cls = False
display = self.display.get()
if display == '0' and key != '.':
self.display.set(key)
else:
if '.' in display and key == '.':
return
self.display.set(display + key)
# 创建组件
def create_widgets(self):
# 显示框
Entry(self, textvariable=self.display, state="readonly", width=35).grid(
row=0, column=0, columnspan=4)
# 键盘
keyboards = [
['C', '+/-', '%', '/'],
['7', '8', '9', '*'],
['4', '5', '6', '-'],
['1', '2', '3', '+'],
['0', '.', '=']
]
for row, keys in enumerate(keyboards):
row_num = 3 + row
for col, key in enumerate(keys):
if key == 'C':
command = self.clear
elif key == '+/-':
command = self.negative
elif key == '%':
command = self.percent
elif key in ['+', '-', '*', '/']:
command = lambda s=key: self.option(s)
elif key == '=':
command = self.calculate
else:
command = lambda s=key: self.input(s)
bt = Button(self, text=key, command=command, width=6)
bt.grid(row=row_num, column=col)
app = Application()
# 设置窗口标题:
app.master.title('www.jb51.net - 计算器')
# 设置窗口尺寸/位置
app.master.geometry("326x170+200+200")
# 设置窗口不可变
app.master.resizable(width=False, height=False)
# 主消息循环:
app.mainloop()
运行效果：
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