大家好,本文将介绍在Python中使用Tkinter几分钟内制作自己的全功能GUI计算器。
要完成所提到的功能,除了通常随Python标准库一起安装的Tkinter之外,不需要任何额外的库。
如果使用的是Linux系统,可能需要安装:
$ pip install python-tk
1.eval()
解决数学问题
eval()
是Python中的一个内置函数,它会解析表达式参数并将其作为Python表达式进行求值,下面使用eval()
的概念来解决数学表达式。
>>> while True:
... expression = input('Enter equation: ')
... result = eval(expression)
... print(result)
...
Enter equation: 2 + (9/9) *3
5.0
Enter equation: 12 /9 + (18 -2) % 5
2.333333333333333
使用这4行代码,已经在Python中制作了一个命令行计算器,现在使用相同的概念来制作一个带有图形界面的计算器。
这个GUI计算器有三个主要部分:
-
用于显示表达式的屏幕(框架)
-
保存表达式值的按钮
-
搭建计算器逻辑
2.为计算器制作框架
from tkinter import Tk, Entry, Button, StringVar
class Calculator:def __init__(self, master):master.title('Simple Calculator')master.geometry('360x260+0+0')master.config(bg='#438')master.resizable(False, False)
root = Tk()
calculator = Calculator(root)
root.mainloop()
输出:
3.添加一个屏幕显示表达式
from tkinter import Tk, Entry, Button, StringVar
class Calculator:def __init__(self, master):master.title('Simple Calculator')master.geometry('360x260+0+0')master.config(bg='#438')master.resizable(False, False)self.equation = StringVar()self.entry_value = ''Entry(width = 28,bg='lightblue', font = ('Times', 16), textvariable = self.equation).place(x=0,y=0)
root = Tk()
calculator = Calculator(root)
root.mainloop()
输出:
如上所示,已经完成显示屏幕的构建,现在需要添加一个按钮用于形成数学表达式。
4.添加用于形成数学表达式的按钮
这些按钮的创建方式相同,只是它们所存储的值和它们的位置不同。用于形成数学表达式的按钮包括:
-
0到9的数字
-
数学运算符+、-、/、%
-
小数点
-
括号()
为每个按钮附加一个命令,以便当点击时,它就会显示在显示屏上。为此,编写一个简单的show()
函数来实现这个功能。
from tkinter import Tk, Entry, Button, StringVar
class Calculator:def __init__(self, master):master.title('Simple Calculator')master.geometry('360x260+0+0')master.config(bg='#438')master.resizable(False, False)self.equation = StringVar()self.entry_value = ''Entry(width = 28,bg='lightblue', font = ('Times', 16), textvariable = self.equation).place(x=0,y=0)Button(width=8, text = '(', relief ='flat', command=lambda:self.show('(')).place(x=0,y=50)Button(width=8, text = ')', relief ='flat', command=lambda:self.show(')')).place(x=90, y=50)Button(width=8, text = '%', relief ='flat', command=lambda:self.show('%')).place(x=180, y=50)Button(width=8, text = '1', relief ='flat', command=lambda:self.show(1)).place(x=0,y=90)Button(width=8, text = '2', relief ='flat', command=lambda:self.show(2)).place(x=90,y=90)Button(width=8, text = '3', relief ='flat', command=lambda:self.show(3)).place(x=180,y=90)Button(width=8, text = '4', relief ='flat', command=lambda:self.show(4)).place(x=0,y=130)Button(width=8, text = '5', relief ='flat', command=lambda:self.show(5)).place(x=90,y=130)Button(width=8, text = '6', relief ='flat', command=lambda:self.show(6)).place(x=180,y=130)Button(width=8, text = '7', relief ='flat', command=lambda:self.show(7)).place(x=0,y=170)Button(width=8, text = '8', relief ='flat', command=lambda:self.show(8)).place(x=180,y=170)Button(width=8, text = '9', relief ='flat', command=lambda:self.show(9)).place(x=90,y=170)Button(width=8, text = '0', relief ='flat', command=lambda:self.show(0)).place(x=0,y=210)Button(width=8, text = '.', relief ='flat', command=lambda:self.show('.')).place(x=90,y=210)Button(width=8, text = '+', relief ='flat', command=lambda:self.show('+')).place(x=270,y=90)Button(width=8, text = '-', relief ='flat', command=lambda:self.show('-')).place(x=270,y=130)Button(width=8, text = '/', relief ='flat', command=lambda:self.show('/')).place(x=270,y=170)Button(width=8, text = 'x', relief ='flat', command=lambda:self.show('*')).place(x=270,y=210)
def show(self, value):self.entry_value +=str(value)self.equation.set(self.entry_value)root = Tk()
calculator = Calculator(root)
root.mainloop()
输出:
输出是一个带有按钮的计算器,当点击其中任意一个按钮时,它的值就会显示在显示屏上。
现在计算器只剩下两个按钮就能完整,一个是重置按钮用于清除屏幕,另一个是等号(=)按钮,用于计算表达式并将结果显示在屏幕上。
5.为计算器添加重置和等号按钮
from tkinter import Tk, Entry, Button, StringVar
class Calculator:def __init__(self, master):master.title('Simple Calculator')master.geometry('360x260+0+0')master.config(bg='#438')master.resizable(False, False)self.equation = StringVar()self.entry_value = ''Entry(width = 28,bg='lightblue', font = ('Times', 16), textvariable = self.equation).place(x=0,y=0)
Button(width=8, text = '(', relief ='flat', command=lambda:self.show('(')).place(x=0,y=50)Button(width=8, text = ')', relief ='flat', command=lambda:self.show(')')).place(x=90, y=50)Button(width=8, text = '%', relief ='flat', command=lambda:self.show('%')).place(x=180, y=50)Button(width=8, text = '1', relief ='flat', command=lambda:self.show(1)).place(x=0,y=90)Button(width=8, text = '2', relief ='flat', command=lambda:self.show(2)).place(x=90,y=90)Button(width=8, text = '3', relief ='flat', command=lambda:self.show(3)).place(x=180,y=90)Button(width=8, text = '4', relief ='flat', command=lambda:self.show(4)).place(x=0,y=130)Button(width=8, text = '5', relief ='flat', command=lambda:self.show(5)).place(x=90,y=130)Button(width=8, text = '6', relief ='flat', command=lambda:self.show(6)).place(x=180,y=130)Button(width=8, text = '7', relief ='flat', command=lambda:self.show(7)).place(x=0,y=170)Button(width=8, text = '8', relief ='flat', command=lambda:self.show(8)).place(x=180,y=170)Button(width=8, text = '9', relief ='flat', command=lambda:self.show(9)).place(x=90,y=170)Button(width=8, text = '0', relief ='flat', command=lambda:self.show(0)).place(x=0,y=210)Button(width=8, text = '.', relief ='flat', command=lambda:self.show('.')).place(x=90,y=210)Button(width=8, text = '+', relief ='flat', command=lambda:self.show('+')).place(x=270,y=90)Button(width=8, text = '-', relief ='flat', command=lambda:self.show('-')).place(x=270,y=130)Button(width=8, text = '/', relief ='flat', command=lambda:self.show('/')).place(x=270,y=170)Button(width=8, text = 'x', relief ='flat', command=lambda:self.show('*')).place(x=270,y=210)Button(width=8, text = '=', bg='green', relief ='flat', command=self.solve).place(x=180, y=210)Button(width=8, text = 'AC', relief ='flat', command=self.clear).place(x=270,y=50)
def show(self, value):self.entry_value +=str(value)self.equation.set(self.entry_value)def clear(self):self.entry_value = ''self.equation.set(self.entry_value)def solve(self):result = eval(self.entry_value)self.equation.set(result)root = Tk()
calculator = Calculator(root)
root.mainloop()
最终输出类似下图的计算器:
在短短的五分钟内就可以成功使用Tkinter库搭建了一个Python GUI计算器,这个计算器可以进行基本的数学运算,并为用户提供了友好的交互体验。
搭建一个GUI计算器不仅仅是一个有趣的项目,它还展示了Python的强大和灵活性。希望本文对大家有所帮助,并激励进一步探索和开发更多有趣的GUI应用程序。