Change label text dynamically based on user Input

Question

I am trying to create an app with 2 python files, the first reads the user input (either from python shell or directly from the keyboard via modules like pynput-keyboard) and stores it in a variable (after space is pressed). Then it sends the original string and a new transform string to the gui's labels.

The second creates the gui that has 2 labels and two buttons and takes the variable passed from the first file and changes the labels based on this variable (the buttons are used for data insert in a later step in a database).

I have created the gui and the python script that reads the input, but I am struggling on passing this variable to the second script and on changing the label dynamically.

Please see the code samples above.

read_user_input.py

import keyboard
import gui

def transform_string(string):
    if len(string)>0:
        return string[0:len(string)-1]
    else:
        return "0"

def logging_function():
    string = ""

    while(True):
        event = keyboard.read_event()
        if (str(event)[-5:-1] == "down"):
            key_pressed = ((str(event).rsplit(' ', 1))[0])[14:]

            if (key_pressed == "space"):
                """PASS THIS string AND transform_string TO OUR GUI's LABELS"""
                print("Pass to gui's labels")
            else:
                string = string + key_pressed




logging_function()

gui.ui



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gui.py

from PyQt5 import QtWidgets, uic
import sys

class Ui(QtWidgets.QMainWindow):
    def __init__(self):
        super(Ui, self).__init__() # Call the inherited classes __init__ method
        uic.loadUi('untitled.ui', self) # Load the .ui file
        self.show() # Show the GUI

app = QtWidgets.QApplication(sys.argv) # Create an instance of QtWidgets.QApplication
window = Ui() # Create an instance of our class
app.exec_() # Start the application

The ui window is the above:

eyllanesc · Accepted Answer

What you have to do is use the pynput listener and analyze the keycode, then according to that build the word and send it by means of a signal to the GUI that according to its own logic add it to the QLabels:

read_user_input.py

from pynput.keyboard import Key, Listener

from PyQt5 import QtCore


class KeyMonitor(QtCore.QObject):
    wordPressed = QtCore.pyqtSignal(str)

    def __init__(self, parent=None):
        super().__init__(parent)
        self.listener = Listener(on_release=self.on_release)
        self.word = ""

    def on_release(self, key):
        if hasattr(key, "char"):
            self.word += key.char
        if key == Key.space:
            self.wordPressed.emit(self.word)
            self.word = ""

    def stop_monitoring(self):
        self.listener.stop()

    def start_monitoring(self):
        self.listener.start()

gui.py

from itertools import cycle
import sys

from PyQt5 import QtCore, QtWidgets, uic

from read_user_input import KeyMonitor


class Ui(QtWidgets.QMainWindow):
    def __init__(self):
        super(Ui, self).__init__()
        uic.loadUi("untitled.ui", self)
        self.show()

        self.labels = cycle([self.label, self.label_2])

    @QtCore.pyqtSlot(str)
    def on_word_pressed(self, word):
        le = next(self.labels)
        le.setText(word)


if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    window = Ui()
    monitor = KeyMonitor()
    monitor.wordPressed.connect(window.on_word_pressed)
    monitor.start_monitoring()
    sys.exit(app.exec_())

Update:

If you want to use the keyboard library then you must use the following:

read_user_input.py

import threading

import keyboard

from PyQt5 import QtCore


class KeyMonitor(QtCore.QObject):
    wordPressed = QtCore.pyqtSignal(str)

    def __init__(self, parent=None):
        super().__init__(parent)
        self.word = ""

        self.listener = threading.Thread(target=self._task, daemon=True)

    def _task(self):
        while True:
            event = keyboard.read_event()
            if event.event_type == keyboard.KEY_DOWN:
                if event.name == "space":
                    self.wordPressed.emit(self.word)
                    self.word = ""
                elif len(event.name) == 1:
                    self.word += event.name

    def start_monitoring(self):
        self.listener.start()

Update:

The logic of modifying the data is a trivial task that consists of converging the "word" and generating the new strings:

import sys

from PyQt5 import QtCore, QtWidgets, uic

from read_user_input import KeyMonitor


class Ui(QtWidgets.QMainWindow):
    def __init__(self):
        super(Ui, self).__init__()
        uic.loadUi("untitled.ui", self)
        self.show()

    @QtCore.pyqtSlot(str)
    def on_word_pressed(self, word):
        try:
            x = int(word)
        except ValueError:
            print("You must enter a whole number")
        else:
            self.label.setText("{}".format(x + 2))
            self.label_2.setText("Changed {}".format(x - 2))


if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    window = Ui()
    monitor = KeyMonitor()
    monitor.wordPressed.connect(window.on_word_pressed)
    monitor.start_monitoring()
    sys.exit(app.exec_())

Change label text dynamically based on user Input

Answers (1)

Update:

Update:

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