Interfacing from Python to GUI

[HMartins]

Hi.

I have written some Python code and is works OK. I now need to, say, interface it better with the user, myself

I got QT Designer and configured some dialogues including a textEdit widget called textEdit_log.

The code which I don’t understand much, looks like this:

from PyQt5.QtWidgets import *
from PyQt5 import uic

def main():
    app = QApplication([])
    window = PlotGUI()
    app.exec_()


if __name__ == '__main__':
    main()


class PlotGUI(QMainWindow):

    def __init__(self):
        super(PlotGUI, self).__init__()
        uic.loadUi("PlotGUI.ui", self)
        self.show()

        self.textEdit_log.append("Hi!")

As a result of last line above “Hi!” shows up in textEdit_log. Perfect

The problem is that I am struggling to find out how can I append text to textEdit_log from outside PlotGUI code, I mean, from ‘regular’ Python code.

Having understood how to solve this problem I will probably solve the other similar difficulties.

I hope this post is according to the rules

Thank you
H. Martins

[Axel_Erfurt]

Don't use from xxx import * !

You can append text for example by using argv

python3 test.py "Hello World"

test.py

from PyQt5 import QtWidgets
import sys 
 
class PlotGUI(QtWidgets.QMainWindow):
 
    def __init__(self):
        super(PlotGUI, self).__init__()
        self.textEdit_log = QtWidgets.QTextEdit()
        self.setCentralWidget(self.textEdit_log)
        self.show()
        self.textEdit_log.append("Hi!")

 
 
if __name__ == '__main__':
    app = QtWidgets.QApplication([])
    window = PlotGUI()
    if len(sys.argv) > 1:
        window.textEdit_log.append(sys.argv[1])
    sys.exit(app.exec_())

[HMartins]

Hi,

Looks like that solution involves application (itself) callings arguments:

On the other side, I am having the following

self.pushButton_Start.clicked.connect(main_proc)
^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'PlotGUI' object has no attribute 'pushButton_Start'

Looks like it does not recognise the other widgets. Could this be caused by having removed:

from PyQt5.QtWidgets import *

Meanwhile I need to send some data from say Python non-windows code to PlotGUI window's textEdit_log, not command line data.

Thanks
H. Martins

[Axel_Erfurt]

It's hard to answer without knowing the code. How do you run that non-windows code?

[HMartins]

It's hard to answer without knowing the code. How do you run that non-windows code?

I mean, nothing related with a GUI, just reading and processing data files, writing files, outputing data to a COM port and printing related staff in PyCharm monitor(?) output.

Of course I can do the job if I scratch the code as circumstances change. I could also use the command line to configure software behaviour but it wold be much easier if these parameter would be configured in a GUI and some intermediate processing massages output to a textEdit widget.

I can't find out the proper syntax to send text from say non GUI related code to the GUI code. Looks like something is missing that I am not aware and can't find out.

Suppose I need to send text from one of my previously written (non GUI) functions to a textEdit widget. I can't find out the proper syntax.

Thanks
H. Martins

[HMartins]

In

class PlotGUI(QMainWindow):

    def __init__(self):
        super(PlotGUI, self).__init__()
        uic.loadUi("PlotGUI.ui", self)
        self.show()

        self.pushButton_Start.clicked.connect(main_proc)

        self.textEdit_log.append("Hi!")

The line:
self.pushButton_Start.clicked.connect(main_proc)

main_proc() has no relation to the graphical environment. The above line makes it all run. What about having messages in the PlotGUI coming from the main_proc()?

H. Martins

[Axel_Erfurt]

You mean something like this? pushButton_Start receives text from the other script.

from PyQt5 import QtWidgets
import sys 
import no_gui
  
class PlotGUI(QtWidgets.QMainWindow):
    def __init__(self):
        super(PlotGUI, self).__init__()
        
        self.setGeometry(50, 50, 400, 300)
        self.textEdit_log = QtWidgets.QTextEdit()
        self.setCentralWidget(self.textEdit_log)
        self.pushButton_Start = QtWidgets.QPushButton("Start")
        self.pushButton_Start.clicked.connect(self.button_clicked)
        self.statusBar().addPermanentWidget(self.pushButton_Start)
        self.textEdit_log.append("Hi!")
        
    def button_clicked(self):
        returned_text = no_gui.send_text()
        self.textEdit_log.append(f"text received from no_gui: {returned_text}")
        self.statusBar().showMessage("reading text from no_gui ...")
 
 
if __name__ == '__main__':
    app = QtWidgets.QApplication([])
    window = PlotGUI()
    window.show()
    sys.exit(app.exec_())

no_gui.py

def send_text():
    my_string = "Hello World"
    return my_string

[HMartins]

I found a solution:

class PlotGUI(QMainWindow):

    def __init__(self):
        super(PlotGUI, self).__init__()
        uic.loadUi("PlotGUI.ui", self)
        self.show()

        global txt_log                     #  <<<<<<<<<<<<<< these two lines
        txt_log = self.textEdit_log  #  <<<<<<<<<<<<<< these two lines

Then a small aggregating (append + repaint) function

def txt2log(str):
    txt_log.append(str)
    txt_log.repaint()

And finnaly,

txt2log("appending text")

placed in any other function is doing the job.

Thank you
H. Martins