"""计算器""":
- from tkinter import *
-
- #创建横条型框架
- def frame(root, side):
- w = Frame(root)
- w.pack(side = side, expand = YES, fill = BOTH)
- return w
- #创建按钮
- def button(root, side, text, command = None):
- w = Button(root, text = text, command = command)
- w.pack(side = side, expand = YES, fill = BOTH)
- return w
- #继承了Frame类,初始化程序界面的布局
- class Calculator(Frame):
- def __init__(self):
-
- Frame.__init__(self)
-
- self.pack(expand = YES, fill = BOTH)
- self.master.title('Simple Calculater')
-
- display = StringVar()
- #添加输入框
- Entry(self, relief = SUNKEN,
- textvariable = display).pack(side = TOP, expand = YES,
- fill = BOTH)
- #添加横条型框架以及里面的按钮
- for key in('123', '456', '789', '-0.'):
- keyF = frame(self, TOP)
- for char in key:
- button(keyF, LEFT, char, lambda w = display, c = char:w.set(w.get() + c))
- #添加操作符按钮
- opsF = frame(self, TOP)
- for char in '+-*/=':
- if char == '=':
- btn = button(opsF, LEFT, char)
- btn.bind('<ButtonRelease - 1>', lambda e, s = self, w = display:s.calc(w), '+')
-
- else:
- btn = button(opsF, LEFT, char, lambda w = display, s = '%s' %char:w.set(w.get() + s))
- #添加清除按钮
- clearF = frame(self, BOTTOM)
- button(clearF, LEFT, 'clear', lambda w = display:w.set(''))
-
- #调用eval函数计算表达式的值
- def calc(self, display):
- try:
- display.set(eval(display.get()))
- except:
- display.set("ERROR")
- #程序的入口
- if __name__ == '__main__':
- print('来啦!!!')
- Calculator().mainloop()
-
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