Add math calculator to GUI

def WriteJogValue(self,button): if len(self.displayLabel.text()) >0: text = float(self.displayLabel.text()) if text > 0 or test <0: self.jogval.setValue(text) else: self.jogval.setValue(0) self.displayLabel.clear()

In such function I need to include such functionality for calculator:
self.displayLabel.text()[code] - is a text from screenwhere I need to get line:
567/2 (for example)
and to return back to this screen integer result: 283 or 285 or 283.5 (and in future programs to convert this float to integer)

How to make such thing?

I Think, I should do it with regular expressions:

Af = re.match(r".*A\s*([\d\.,]+)", line)

    def Calc(self, button):
        if len(self.displayLabel.text()) >0:
            equation = self.displayLabel.text()
            x=0
            if '+' in equation:
                y = equation.split('+')
                x = float(y[0])+float(y[1])
            elif '-' in equation:
                y = equation.split('-')
                x = float(y[0])-float(y[1])
            elif '/' in equation:
                y = equation.split('/')
                x = float(y[0])/float(y[1])
            elif '*' in equation:
                y = equation.split('*')
                x = float(y[0])*float(y[1])
            self.displayLabel.setNum(x)

    def numKeyboard(self, button):
        text = self.displayLabel.text() # copy the label text to the variable
        if len(text) > 0: # if there is something in the label
            text += button.text() # add the button text to the text variable
        else: # if the label is empty
            text = button.text() # assign the button text to the text variable
        self.displayLabel.setText(text) # set the text in label

[code]>>> # Arithmetic operations
>>> eval("5 + 7")
12
>>> eval("5 * 7")
35
>>> eval("5 ** 7")
78125
>>> eval("(5 + 7) / 2")
6.0
>>> import math
>>> # Area of a circle
>>> eval("math.pi * pow(25, 2)")
1963.4954084936207
>>> # Volume of a sphere
>>> eval("4 / 3 * math.pi * math.pow(25, 3)")
65449.84694978735
>>> # Hypotenuse of a right triangle
>>> eval("math.sqrt(math.pow(10, 2) + math.pow(15, 2))")
18.027756377319946