Beleg/taschenrechn...

from Tkinter import *

def toList(text):
	a = text.splitlines()
    L = []
    for i in a:
            s = ""
            z = True
            for j in i:
                    #print j
                    if j not in '+-*/':
                            s += j
                            z = True
                    else:
                            if s:
                                    L.append(s)
                            if j:
                                    L.append(j)
                            s = ""
                            z = False
            if i[-1] in '+-*/':
                    if z and j:
                            L.append(j)
            else:
                    if z and s:
                            L.append(s)
    return L

def Stack(i,s,S = None):

    if not S:
        S = []
        
    if i == len(s):
        return S[0]

    a = s[i]
    if a.isdigit():
        S.append(a)
        return Stack(s, S, i+1)
    else:
        c = S.pop()
        d = S.pop()
        
        S.append(Grundrechenarten(d,a,c))
        return Stack(s, S, i+1)

def Grundrechenarten(c,a,d):

    if a == '+':
        result = float(c)+float(d)
    elif a == '-':
        result = float(c)-float(d)
    elif a == '*':
        result = float(c)*float(d)
    elif a == '/':
        result = float(c)/float(d)

    if result == int(result):
        result = int(result)

    return result

#-----------------------------

def response(event):
    I = event.widget['text']
    
    texts = UPN.text.get(1.0,END+'-1c')
    #print texts

    if I == 'DEL':
        UPN.text.delete(INSERT + '-1c',INSERT)
    elif I == 'Clear':
        UPN.text.delete(1.0,END)
    elif I == 'Enter':
        UPN.text.insert(INSERT,'\n')
    elif I == '=':
        s = toList(texts)
        #print s
        UPN.text.insert(END,'\n=\n')
        UPN.text.insert(END,f(s))
        UPN.text.see('end')
def UPN():    
    root.title('umgekehrte polnische Notation')
    root.geometry('400x500+200+100')

    UI = LabelFrame(root)
    UI.place(x = 1,y = 1,width = 398,height = 124)

    UPN.text = Text(UI)
    UPN.text.place(x=1,y=1,width=390,height=116)

    Li=[['7','8','9','+','DEL'],
        ['4','5','6','-','Enter'],
        ['1','2','3','*','='],
        ['0','00','.','/','Clear']]
 
    for i in range(len(Li[0])):
        for j in range(len(Li)):
            bt = Button(root)
            bt.place(x=(i+1)*60,y=120+(j+1)*60,width=50,height=50)
            bt['text'] = Li[j][i]
            bt.bind('<Button-1>',response,add=(root,))

def main():
    UPN()
    root.mainloop()

if __name__ == '__main__':
    root = Tk()
    main()