How to avoid Null or empty value in QLineedit of Pyqt5

Lalremruata

I tried to validate the QLineedit not to be empty without success.

I did

validator = QRegExpValidator(QRegExp(r'[0-9]+')) 
self.lineEdit_2.setValidator(validator)

it is working.

But

def temp_var(self, text):
cur_txt = text
if cur_txt == 'Cheque' or cur_txt == 'Wire Transfer' or self.lineEdit_2.text() == "":
self.groupBox_3.show()
self.pushButton_7.hide()
self.pushButton_7.setEnabled(False)

else:
self.groupBox_3.hide()
self.pushButton_7.show()
self.pushButton_7.setEnabled(True)

all works fine but the pushbutton is always enabled even the self.lineEdit_2 is empty.

I request your help. (I am a self-learner and could not find solution in the web.

jsulm

@Lalremruata said in How to avoid Null or empty value in QLineedit of Pyqt5:

or self.lineEdit_2.text() == ""

You should rather use https://doc.qt.io/qt-5/qstring.html#isEmpty

JonB

@Lalremruata said in How to avoid Null or empty value in QLineedit of Pyqt5:

even the self.lineEdit_2 is empty.

Are you really 100% sure? I used PyQt5 and I'm pretty sure self.lineEdit_2.text() == "" would work as expected. Get rid of all your other code and behaviour and check just this in a tiny program?

@jsulm

You should rather use https://doc.qt.io/qt-5/qstring.html#isEmpty

My understanding is PyQt5's QLineEdit.text() returns a Python str rather than a C++ QString anyway. I never found using QString methods of any use in PyQt5.