python例程 (1).rar_Python 例程_python_python例程

from tkinter import * root = Tk() # 计算机窗口大小 （宽x高） root.geometry("250x380") # 设置计算机title root.title("计算器") # Frame就是在屏幕上的一块矩形区域 多用来作为容器使用 frame_show = Frame(width=250, height=150, bg='#ddd') # 添加到主窗体 frame_show.pack() # 主窗体 # 实例化一个产生变量的类 v = StringVar() # 初始化赋值'0' v.set('0') # Lable(用于存放父组件，属性参数 ) # anchor 文本相对于标签中心的位置 默认是center N S W E show_label = Label(frame_show, textvariable=v, bg='white', width='30', height='1', anchor='e', font=("黑体", 20, "bold")) # 添加到主窗体 show_label.pack(padx=10, pady=10) frame_bord = Frame(width=250, height=350, bg='#ccc') frame_bord.pack(padx=10, pady=10) calc = [] isoperate = False def change(num): global isoperate if isoperate == False: if v.get() == "0" and num == '.': v.set(length(v.get() + num)) elif v.get() == "0": v.set(length(num)) else: if num == ".": if v.get().count(".") < 1: v.set(v.get() + num) else: v.set(v.get() + num) else: v.set(length(num)) isoperate = False # 检验字符串的长度的函数 def length(str): if len(str) > 12: return str[0:12] else: return str # 清空函数 def clear(): global calc calc = [] # 屏幕窗口恢复到0 v.set("0") # 操作 + - * / def operate(sign): global calc global isoperate isoperate = True calc.append(v.get()) if sign == "+": calc.append(sign) elif sign == "-": calc.append(sign) elif sign == "*": calc.append(sign) elif sign == "/": calc.append(sign) # 运算 global calcstr def equal(): global calc # 获取当前界面的值 calc.append(v.get()) print(calc) # 列表变字符串 join 把列表用什么拼接成字符串 calcstr = "".join(calc) print(calcstr) print(type(calcstr)) # 运算操作 eval（）把str当成有效的表达式进行计算 result = eval(calcstr) if len(str(result)) > 12: result = str(result) result = result[0:12] v.set(result) else: v.set(result) print(result) # 定义退格函数 def delete(): # 获取v.get（）长度 num = len(v.get()) # 如果长度>1 怎么办 if num > 1: strnum = v.get() strnum = strnum[0:num - 1] v.set(strnum) # 小于等于1的时候 else: v.set("0") #正负操作 def fan(): strnum = v.get() if strnum[0] == '-': v.set(strnum[1:]) elif strnum[0] != '-' and strnum != '0' : v.set('-'+strnum) # Button(父组件，属性参数) button_del = Button(frame_bord, text='←', width='5', height='1', command=lambda: delete()).grid(row='1', column='0') button_del = Button(frame_bord, text='CE', width='5', height='1', command=lambda: clear()).grid(row='1', column='1') button_del = Button(frame_bord, text='C', width='5', height='1', command=lambda: clear()).grid(row='1', column='2') button_del = Button(frame_bord, text='±', width='5', height='1', command=lambda: fan()).grid(row='1', column='3') button_del = Button(frame_bord, text='7', width='5', height='1', command=lambda: change("7")).grid(row='2', column='0') button_del = Button(frame_bord, text='8', width='5', height='1', command=lambda: change("8")).grid(row='2', column='1') button_del = Button(frame_bord, text='9', width='5', height='1', command=lambda: change("9")).grid(row='2', column='2') button_del = Button(frame_bord, text='/', width='5', height='1', command=lambda: operate("/")).grid(row='2', column='3') button_del = Button(frame_bord, text='4', width='5', height='1', command=lambda: change("4")).grid(row='3', column='0') button_del = Button(frame_bord, text='5', width='5', height='1', command=lambda: change("5")).grid(row='3', column='1') button_del = Button(frame_bord, text='6', width='5', height='1', command=lambda: change("6")).grid(row='3', column='2') button_del = Button(frame_bord, text='-', width='5', height='1', command=lambda: operate("-")).grid(row='3', column='3') button_del = Button(frame_bord, text='1', width='5', height='1', command=lambda: change("1")).grid(row='4', column='0') button_del = Button(frame_bord, text='2', width='5', height='1', command=lambda: change("2")).grid(row='4', column='1') button_del = Button(frame_bord, text='3', width='5', height='1', command=lambda: change("3")).grid(row='4', column='2') button_del = Button(frame_bord, text='*', width='5', height='1', command=lambda: operate("*")).grid(row='4', column='3') button_del = Button(frame_bord, text='0', width='5', height='1', command=lambda: change("0")).grid(row='5', column='0') button_del = Button(frame_bord, text='.', width='5', height='1', command=lambda: change(".")).grid(row='5', column='1') button_del = Button(frame_bord, text='+', width='5', height='1', command=lambda: operate("+")).grid(row='5', column='2') button_del = Button(frame_bord, text='=', width='5', height='1', command=lambda: equal()).grid(row='5', column='3') button_del = Button(frame_bord, text='查看作者', width='25', height='1', command=lambda: print("twilight")).grid(row='6',columnspan='4') root.mainloop()