Error pressing QPushButton

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Error pressing QPushButton

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#1 by (2 votes)

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Dear I have a small application in pyqt5 and QT DESIGNER.

The application works well only when you run the "clean" button the application stops working.

I leave the code to see if someone can help me where the error is generated.

untitled.py

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'untitled.ui'
#
# Created by: PyQt5 UI code generator 5.9.2
#
# WARNING! All changes made in this file will be lost!

from PyQt5 import QtCore, QtGui, QtWidgets

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(400, 200)
        MainWindow.setMinimumSize(QtCore.QSize(400, 200))
        MainWindow.setMaximumSize(QtCore.QSize(400, 200))
        font = QtGui.QFont()
        font.setBold(False)
        font.setItalic(False)
        font.setUnderline(False)
        font.setWeight(50)
        font.setStrikeOut(False)
        MainWindow.setFont(font)
        MainWindow.setMouseTracking(False)
        icon = QtGui.QIcon()
        icon.addPixmap(QtGui.QPixmap("icon.ico"), QtGui.QIcon.Normal, QtGui.QIcon.On)
        MainWindow.setWindowIcon(icon)
        MainWindow.setIconSize(QtCore.QSize(25, 25))
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.label_3 = QtWidgets.QLabel(self.centralwidget)
        self.label_3.setGeometry(QtCore.QRect(350, 180, 41, 20))
        self.label_3.setObjectName("label_3")
        self.widget = QtWidgets.QWidget(self.centralwidget)
        self.widget.setGeometry(QtCore.QRect(60, 80, 297, 63))
        self.widget.setObjectName("widget")
        self.verticalLayout = QtWidgets.QVBoxLayout(self.widget)
        self.verticalLayout.setContentsMargins(0, 0, 0, 0)
        self.verticalLayout.setObjectName("verticalLayout")
        self.horizontalLayout_2 = QtWidgets.QHBoxLayout()
        self.horizontalLayout_2.setObjectName("horizontalLayout_2")
        self.valor1 = QtWidgets.QLineEdit(self.widget)
        self.valor1.setObjectName("valor1")
        self.horizontalLayout_2.addWidget(self.valor1)
        self.valor2 = QtWidgets.QLineEdit(self.widget)
        self.valor2.setObjectName("valor2")
        self.horizontalLayout_2.addWidget(self.valor2)
        self.verticalLayout.addLayout(self.horizontalLayout_2)
        self.horizontalLayout = QtWidgets.QHBoxLayout()
        self.horizontalLayout.setObjectName("horizontalLayout")
        self.btn1 = QtWidgets.QPushButton(self.widget)
        self.btn1.setObjectName("btn1")
        self.horizontalLayout.addWidget(self.btn1)
        self.btn2 = QtWidgets.QPushButton(self.widget)
        self.btn2.setObjectName("btn2")
        self.horizontalLayout.addWidget(self.btn2)
        self.btn3 = QtWidgets.QPushButton(self.widget)
        self.btn3.setObjectName("btn3")
        self.horizontalLayout.addWidget(self.btn3)
        self.verticalLayout.addLayout(self.horizontalLayout)
        self.widget1 = QtWidgets.QWidget(self.centralwidget)
        self.widget1.setGeometry(QtCore.QRect(61, 51, 291, 23))
        self.widget1.setObjectName("widget1")
        self.gridLayout = QtWidgets.QGridLayout(self.widget1)
        self.gridLayout.setContentsMargins(0, 0, 0, 0)
        self.gridLayout.setObjectName("gridLayout")
        self.label = QtWidgets.QLabel(self.widget1)
        self.label.setObjectName("label")
        self.gridLayout.addWidget(self.label, 0, 0, 1, 1)
        self.label_2 = QtWidgets.QLabel(self.widget1)
        self.label_2.setObjectName("label_2")
        self.gridLayout.addWidget(self.label_2, 0, 1, 1, 1)
        MainWindow.setCentralWidget(self.centralwidget)

        self.retranslateUi(MainWindow)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "Conversor"))
        self.label_3.setText(_translate("MainWindow", "<html><head/><body><p align=\"center\">V 1.0</p></body></html>"))
        self.btn1.setText(_translate("MainWindow", "calcular"))
        self.btn2.setText(_translate("MainWindow", "limpiar"))
        self.btn3.setText(_translate("MainWindow", "salir"))
        self.label.setText(_translate("MainWindow", "<html><head/><body><p align=\"center\"><span style=\" font-size:10pt; font-weight:600;\">Mts * Seg</span></p></body></html>"))
        self.label_2.setText(_translate("MainWindow", "<html><head/><body><p align=\"center\"><span style=\" font-size:10pt; font-weight:600;\">Km*H</span></p></body></html>"))


if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_MainWindow()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

converter.py

from PyQt5 import QtWidgets, QtGui
from untitled import Ui_MainWindow


class MainWindow(QtWidgets.QMainWindow, Ui_MainWindow):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.setupUi(self)

        self.btn3.clicked.connect(self.close)
        self.valor1.textChanged.connect(self.calcmts)
        self.valor1.setValidator(QtGui.QDoubleValidator())
        self.valor2.setValidator(QtGui.QDoubleValidator())
        self.btn2.clicked.connect(self.valor1.clear)
        self.btn2.clicked.connect(self.valor2.clear)

    def calcmts(self):
        conversion = float(self.valor1.text()) * 3.6
        self.valor2.setText(str(conversion))


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    MainWindow = MainWindow()
    MainWindow.show()
    sys.exit(app.exec_())

python python-3.x pyqt pyqt5

asked by Bruno Oviedo 23.12.2017 в 02:08

source

1 answer

Problem when traversing an array in javascript in_array PHP Warning

score 2 · Accepted Answer

I recommend you run your application from the cmd and review the error messages as they are very important, with your code this message was produced:

Traceback (most recent call last):
  File "conversor.py", line 18, in calcmts
    conversion = float(self.valor1.text()) * 3.6
ValueError: could not convert string to float:
Aborted (core dumped)

This indicates that it has problems converting a string to float, the reason is that when using the clear () method, the text is changed so that the textChanged () signal from self.valor1 will be emitted, and it will invoke the function calcmts (), this will try to convert the empty string to float and obviously this is not possible, the solution is to make a code that validates that the text is not an empty string:

def calcmts(self):
    if self.valor1.text() != "":
        conversion = float(self.valor1.text()) * 3.6
        self.valor2.setText(str(conversion))