from __future__ import division
import sys
from math import *
from PyQt4.QtCore import *
from PyQt4.QtGui import *
class Form(QDialog):
def __init__(self,parent=None):
super(Form,self).__init__(parent)
self.browser=QTextBrowser()
self.Lineedit=QLineEdit('Type an expression and press Enter')
self.Lineedit.selectAll()
layout=QVBoxLayout()
layout.addWidget(self.browser)
layout.addWidget(self.Lineedit)
self.setLayout(layout)
self.Lineedit.setFocus()
self.connect(self.Lineedit,SIGNAL('returnPressed()'),self.updateUi)
self.setWindowTitle('calculate')
def updateUi(self):
try:
text=unicode(self.Lineedit.text())
self.browser.append('%s = <b>%s</b>' % (text,eval(text)))
except:
self.browser.append('<font color=red>%s is invalid!</font>' % text)
app=QApplication(sys.argv)
form=Form()
form.show()
app.exec_()
