检查输入Pyqt4

Question

I want to check if the user has inputed a string if an integer is enetered then an error is thrown asking the user to re-enter a string so the okay button is rejected I also want the same if nothing is inputed by the user so no string.

import sys
from PyQt4 import QtGui


class Example(QtGui.QWidget):

    def __init__(self):
        super(Example, self).__init__()

        self.initUI()

    def initUI(self):      

        self.btn = QtGui.QPushButton('Dialog', self)
        self.btn.move(20, 20)
        self.btn.clicked.connect(self.showDialog)

        self.le = QtGui.QLineEdit(self)
        self.le.move(130, 22)

        self.setGeometry(300, 300, 290, 150)
        self.setWindowTitle('Input dialog')
        self.show()

    def showDialog(self):

        text, ok = QtGui.QInputDialog.getText(self, 'Input Dialog', 
            'Enter your name:')

        if ok:
            self.le.setText(str(text))

def main():

    app = QtGui.QApplication(sys.argv)
    ex = Example()
    sys.exit(app.exec_())


if __name__ == '__main__':
    main()

How do I apply this to the above code?

Im using Pyqt4, for Python 3.

Thanks in advance

Answer 1

I don't have PyQt4, but I'm assuming my code samples are still applicable. But either way, the code you have given accepts (If I'm not mistaken) the name as a string. So, if you check if it's a integer or not, it will never be an integer, due to you accepting an answer as a string.

As for the being blank thing, here's my code:

#Start a while loop to repeatedly ask.
while True:

    #A flag to help with detecting if it's a blank string.
    noneFlag = True

    #The equivalent of your  
    name = input("Your name: ")

    #A for loop - It checks if the string is nothing but blanks, or is nothing. 
    for char in name:

        if char != " ":
            noneFlag = False
            break

    #Responds on if the name is blank or not.
    if noneFlag:
        print("Name field is blank.")
    else:
        #Breaks the loop.
        break

NOTE: Bear in mind that your line:

text, ok = QtGui.QInputDialog.getText(self, 'Input Dialog', 
        'Enter your name:')

is the equivalent of my input statement.

--- EDIT ---

Okay, here's the code you wanted; although bear in mind that unless you change to code to accept the variable as an int, it will never view it as an integer.

if noneFlag:
    print("Name field is blank.")
elif isinstance(name, int):
    print("Name field is an int.")
else:
    break

In essence, what I'm saying is that Python cannot and will not detect if a variable is numbers if it's in a string. For example: "1234567890" as a STRING will not be classed as an integer, as the actual type is a string.