Python using variable outside of a function (and class)

Question

i am using PyQt5 to open a browser to get a folder and assign it to a variable folder_path, if i print it inside the function it works:

def browse_folder(self):
        global folder_path
        options = QtWidgets.QFileDialog.Options()
        options |= QtWidgets.QFileDialog.ReadOnly
        folder_path = QtWidgets.QFileDialog.getExistingDirectory(
            self, "Select Folder", options=options)
        if folder_path:
            global folder_path
            self.folder_line_edit.setText(folder_path)

            self.folder_path = folder_path
            print(folder_path + 'dddwdadds')
            return folder_path

the return and the global is my try to use the variable outside the function and class so when i press submit the windows is gone and the code continues so i can use the variable, i have tried everything.
the last part of the code is:

if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    main_window = MyApp()
    main_window.show()

    # Tamanho da window
    main_window.setGeometry(400, 400, 400, 200)
    sys.exit(app.exec_())
   

# i cannot get this to print
print(folder_path + 'ddd')

Full code:

from PyQt5 import QtWidgets, QtGui, QtCore

import sys

global folder_path


class MyApp(QtWidgets.QMainWindow):
    def __init__(self):

        super().__init__()

        self.setWindowTitle("Creator")

        # Create a central widget for the main window
        self.central_widget = QtWidgets.QWidget()
        self.setCentralWidget(self.central_widget)

        # Create a grid layout for the central widget
        self.grid_layout = QtWidgets.QGridLayout()
        self.central_widget.setLayout(self.grid_layout)

        ......

        self.submit_button.clicked.connect(self.submit_button_clicked)
        self.exit_button.clicked.connect(QtWidgets.QApplication.quit)
  

       def browse_folder(self):
        global folder_path
        options = QtWidgets.QFileDialog.Options()
        options |= QtWidgets.QFileDialog.ReadOnly
        folder_path = QtWidgets.QFileDialog.getExistingDirectory(
            self, "Select Folder", options=options)
        if folder_path:
            global folder_path
            self.folder_line_edit.setText(folder_path)

            self.folder_path = folder_path
            print(folder_path + 'dddwdadds')
            return folder_path

    def browse_file(self):
        global file_path
        options = QtWidgets.QFileDialog.Options()
        options |= QtWidgets.QFileDialog.ReadOnly
        file_path, _ = QtWidgets.QFileDialog.getOpenFileName(
            self, "Select File", options=options)
        if file_path:
            self.file_line_edit.setText(file_path)
            self.file_path = file_path
            return file_path

    def submit_button_clicked(self):

        QtWidgets.QApplication.quit()


if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    main_window = MyApp()
    main_window.show()

    # Tamanho da window
    main_window.setGeometry(400, 400, 400, 200)
    sys.exit(app.exec_())
    

print(folder_path + 'ddd')

Asked By: Rose

||

Source

Answer 1

Does it really have to be in PyQt5 ?

The library "easygui" is really easy to use for simple GUI task like this.

To get a directory, I recommend using easygui.diropenbox

You can simply do :

folder_path = easygui.diropenbox("Choose a folder")

Answered By: gee3107

Answer 2

If you want file_path and folder_path to be global variables you need to define them in the global scope prior to trying to assign them values from within a function or class.

I am not entirely sure why you would need to do this but here is an example using the code you provided.

from PyQt5 import QtWidgets, QtGui, QtCore
import sys

folder_path = None  # define variables in global scope
file_path = None


class MyApp(QtWidgets.QMainWindow):
    def __init__(self):
        super().__init__()
        ...
        ...

    def browse_folder(self):
        global folder_path  # this will work since the variable is already defined
        options = QtWidgets.QFileDialog.Options()
        options |= QtWidgets.QFileDialog.ReadOnly
        path = QtWidgets.QFileDialog.getExistingDirectory(
            self, "Select Folder", options=options)
        if path:
            self.folder_line_edit.setText(path)
            self.folder_path = path
            print(path + 'dddwdadds')
            folder_path = path   # and this will set the new value

    def browse_file(self):
        global file_path    # file_path was already defined 
        options = QtWidgets.QFileDialog.Options()
        options |= QtWidgets.QFileDialog.ReadOnly
        path, _ = QtWidgets.QFileDialog.getOpenFileName(
            self, "Select File", options=options)
        if path:
            self.file_line_edit.setText(path)
            self.file_path = path
            file_path = path   # this will set a new value to file_path

    def submit_button_clicked(self):
        QtWidgets.QApplication.quit()


if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    main_window = MyApp()
    main_window.show()
    # Tamanho da window
    main_window.setGeometry(400, 400, 400, 200)
    app.exec_()   # if you wrap this line with sys.exit() nothing that comes after will execute
    print(folder_path, file_path)  # this line will print the paths chosen once the window exits

Answered By: Alexander

Python using variable outside of a function (and class)

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