如何用tkinter製作Python的GUI(圖形使用者介面)? 如何做出計算機? eval() 可將字串還原為python指令

by 儲蓄保險王 · 2023-03-21

from tkinter import * #會造成變數汙染,最好不要這樣用

class Calculator:

   

    def replaceAndEval(self):

        text = self.e.get()             # “2 + 8 ÷ 2 + 3 x 2”

        text = text.replace(“x”, “*”)   # “2 + 8 ÷ 2 + 3 * 2”

        text = text.replace(“÷”, “/”)   # “2 + 8 / 2 + 3 * 2”

        result = eval( text )

        return result

    def equals(self):

        result = self.replaceAndEval()

        self.allClear()

        self.e.insert(0, result)

    def square(self):

        text = self.replaceAndEval()

        result = text ** 2

        self.allClear()

        self.e.insert(0, result)

    def squareRoot(self):

        text = self.replaceAndEval()

        result = text ** 0.5

        self.allClear()

        self.e.insert(0, result)

    def clearOne(self):

        text = self.e.get()[0:-1]

        self.allClear()

        self.e.insert(0, text)  

    def allClear(self):

        self.e.delete(0, END)

    def enterChar(self, symbol):

        self.e.insert(END, symbol)

       

    def __init__(self, window):

“”” 參數window只在__init__()

這個function使用到,

沒有使用self.window承接這個參數

__init__() 的縮排內,

就可以只寫window

不用寫self.window

但若class內的其他function

也要用window這個參數

這種寫法就不一定方便,

要把window也傳去別的function “””

        self.e = Entry(window, width=28)

        self.e.grid(row=0, column=0, columnspan=8)

        self.e.focus()

        Button(window, text=”=”, width=8, command=self.equals).grid(row=4, column=4, columnspan=2)

        Button(window, text=”AC”, width=3, command=self.allClear).grid(row=1, column=4)

        Button(window, text=”C”, width=3, command=self.clearOne).grid(row=1, column=5)

        Button(window, text=”√”, width=3, command=self.squareRoot).grid(row=3, column=4)

        Button(window, text=”x²”, width=3, command=self.square).grid(row=3, column=5)

        Button(window, text=”+”, width=3, command=lambda:self.enterChar(“+”) ).grid(row=4, column=3)

        Button(window, text=”x”, width=3, command=lambda:self.enterChar(“x”) ).grid(row=2, column=3)

        Button(window, text=”-“, width=3, command=lambda:self.enterChar(“-“) ).grid(row=3, column=3)

        Button(window, text=”÷”, width=3, command=lambda:self.enterChar(“÷”) ).grid(row=1, column=3)

        Button(window, text=”%”, width=3, command=lambda:self.enterChar(“%”) ).grid(row=4, column=2)

        Button(window, text=”7″, width=3, command=lambda:self.enterChar(“7”) ).grid(row=1, column=0)

        Button(window, text=”8″, width=3, command=lambda:self.enterChar(“8”) ).grid(row=1, column=1)

        Button(window, text=”9″, width=3, command=lambda:self.enterChar(“9”) ).grid(row=1, column=2)

        Button(window, text=”4″, width=3, command=lambda:self.enterChar(“4”) ).grid(row=2, column=0)

        Button(window, text=”5″, width=3, command=lambda:self.enterChar(“5”) ).grid(row=2, column=1)

        Button(window, text=”6″, width=3, command=lambda:self.enterChar(“6”) ).grid(row=2, column=2)

        Button(window, text=”1″, width=3, command=lambda:self.enterChar(“1”) ).grid(row=3, column=0)

        Button(window, text=”2″, width=3, command=lambda:self.enterChar(“2”) ).grid(row=3, column=1)

        Button(window, text=”3″, width=3, command=lambda:self.enterChar(“3”) ).grid(row=3, column=2)

        Button(window, text=”0″, width=3, command=lambda:self.enterChar(“0”) ).grid(row=4, column=0)

        Button(window, text=”.”, width=3, command=lambda:self.enterChar(“.”) ).grid(row=4, column=1)

        Button(window, text=”(“, width=3, command=lambda:self.enterChar(“(“) ).grid(row=2, column=4)

        Button(window, text=”)”, width=3, command=lambda:self.enterChar(“)”) ).grid(row=2, column=5)

root = Tk()

calc = Calculator(root)

root.mainloop()

推薦hahow線上學習python: https://igrape.net/30afN

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儲蓄險是板主最喜愛的儲蓄工具,最喜愛的投資理財工具則是ETF,最喜愛的省錢工具則是信用卡

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