Back to Previous Window - python-3.x

Question

i'm new in Python and PyQt4.
I want to ask "How to back to previous Window ?"
i have 2 file in here, file 'login' and 'signup'
here file login.py
import sys
from PyQt4.QtGui import QWidget, QPushButton, QLineEdit, QLabel, \
QApplication, QGridLayout
from signup import SignUp
class Login(QWidget):
def __init__(self):
super(Login, self).__init__()
self.setWindowTitle("Login")
self.login_window()
def login_window(self):
self.login_layout = QGridLayout()
self.login_button = QPushButton("Login")
self.signup_button = QPushButton("Sign Up")
self.login_layout.addWidget(self.login_button, 2, 0)
self.login_layout.addWidget(self.signup_button, 2, 1)
self.signup_button.clicked.connect(self.signup_show)
self.setLayout(self.login_layout)
self.show()
def signup_show(self):
self.signupshow = SignUp()
self.hide()
self.signupshow.show()
def check_signup(self):
SignUp.check_signup()
self.show()
def main():
app = QApplication(sys.argv)
login = Login()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
and here is signup.py
import sys
from PyQt4.QtGui import QWidget, QPushButton, QLineEdit, QLabel, \
QApplication, QGridLayout
class SignUp(QWidget):
def __init__(self):
super(SignUp, self).__init__()
self.setWindowTitle("Sign Up")
self.signup_window()
def signup_window(self):
self.signup_layout = QGridLayout()
self.signup_button = QPushButton("Sign Up")
self.signup_layout.addWidget(self.signup_button, 2, 0, 1, 0)
self.signup_button.clicked.connect(self.check_signup)
self.setLayout(self.signup_layout)
self.show()
def check_signup(self):
self.close()
def main():
app = QApplication(sys.argv)
signup = SignUp()
sys.exit(app.exec_())
if __name__ == '__main__':
main()
my problem is, when i push button signup from signup.py, it's close but window Login is not show.
i think i don't have any trigger in signup.py for check_signup in login.py
in this code, i delete some Line Edit and Label. I think it's not a problem.
i hope someone will help, Thank you before :)
and if you answer this questtion, i hope you will explain a little bit of the logic, thank you again :)

Answer 1

I'm not really sure what you are trying to achieve (your description is kind of confusing), but let's start here. I put all your code in one file, since you need to import each other (which leads to cyclic import). Then, I just added these two lines
self.login = Login()
self.login.show()
into check_signup method of SignUp class, which pops-up Login window. If this is not your desired result, please let us know and provide us a better description. The code follows:
import sys
from PyQt4.QtGui import QWidget, QPushButton, QLineEdit, QLabel, \
QApplication, QGridLayout
class Login(QWidget):
def __init__(self):
super(Login, self).__init__()
self.setWindowTitle("Login")
self.login_window()
def login_window(self):
self.login_layout = QGridLayout()
self.login_button = QPushButton("Login")
self.signup_button = QPushButton("Sign Up")
self.login_layout.addWidget(self.login_button, 2, 0)
self.login_layout.addWidget(self.signup_button, 2, 1)
self.signup_button.clicked.connect(self.signup_show)
self.setLayout(self.login_layout)
self.show()
def signup_show(self):
self.signupshow = SignUp()
self.hide()
self.signupshow.show()
def check_signup(self):
SignUp.check_signup()
self.show()
class SignUp(QWidget):
def __init__(self):
super(SignUp, self).__init__()
self.setWindowTitle("Sign Up")
self.signup_window()
def signup_window(self):
self.signup_layout = QGridLayout()
self.signup_button = QPushButton("Sign Up")
self.signup_layout.addWidget(self.signup_button, 2, 0, 1, 0)
self.signup_button.clicked.connect(self.check_signup)
self.setLayout(self.signup_layout)
self.show()
def check_signup(self):
self.login = Login()
self.login.show()
self.close()
def main():
app = QApplication(sys.argv)
signup = SignUp()
sys.exit(app.exec_())
if __name__ == '__main__':
main()

Answer 2

You should rather use signal-slot connections:
import sys
from PyQt4 import QtGui, QtCore
class WidgetA(QtGui.QWidget):
open_b = QtCore.pyqtSignal()
def __init__(self, parent=None):
super(WidgetA, self).__init__(parent)
self.resize(100, 100)
self.l = QtGui.QVBoxLayout()
self.close_btn = QtGui.QPushButton('Close')
self.b_btn = QtGui.QPushButton('Open B')
self.b_btn.clicked.connect(self.b_btn_clicked)
self.l.addWidget(self.close_btn)
self.l.addWidget(self.b_btn)
self.setLayout(self.l)
def b_btn_clicked(self):
self.open_b.emit()
self.hide()
class WidgetB(QtGui.QWidget):
open_a = QtCore.pyqtSignal()
def __init__(self, parent=None):
super(WidgetB, self).__init__(parent)
self.resize(100, 100)
self.l = QtGui.QVBoxLayout()
self.close_btn = QtGui.QPushButton('Close')
self.close_btn.clicked.connect(self.hide)
self.a_btn = QtGui.QPushButton('Open A')
self.a_btn.clicked.connect(self.a_btn_clicked)
self.l.addWidget(self.close_btn)
self.l.addWidget(self.a_btn)
self.setLayout(self.l)
def a_btn_clicked(self):
self.open_a.emit()
self.hide()
def main():
app = QtGui.QApplication(sys.argv)
a = WidgetA()
b = WidgetB()
a.open_b.connect(lambda: b.show())
b.open_a.connect(lambda: a.show())
a.show()
sys.exit(app.exec_())
if __name__ == '__main__':
main()