测试 pyqt 应用程序 - Qwidget：必须在 qwidget 之前构建 qapplication

Question

我有一个 pyqt 应用程序，喜欢测试用于测试该应用程序的脚本。

我能够在独立测试期间构建 qapplication。不确定如何在使用 pytest 编写我的单元测试用例时创建此对象。

import sys

from PyQt5.QtWidgets import QApplication, QDialog, QGridLayout, QLabel, QLineEdit


class Example(QDialog):
    def __init__(self, *args, **kwargs):
        super(Example, self).__init__(*args, **kwargs)            
        self.initUI()

    def initUI(self):
        grid = QGridLayout(self)
        a1 = QLabel('alphanumeric characters')
        a2 = QLabel('alphanumeric characters')

        grid.addWidget(QLabel('Name'), 0, 0)
        grid.addWidget(QLineEdit(), 0, 1)
        grid.addWidget(QLabel('Street1'), 1, 0)
        grid.addWidget(QLineEdit(), 1, 1)
        grid.addWidget(QLabel('Street2'), 2, 0)
        grid.addWidget(QLineEdit(), 2, 1)
        grid.addWidget(QLabel('City'), 3, 0)
        grid.addWidget(QLineEdit(), 3, 1)

        grid.addWidget(QLabel('only alphanumeric'), 0, 2, 4, 1)

        self.setGeometry(500, 500, 500, 500)
        self.setWindowTitle('Lines')
        self.show()

if __name__ == '__main__':

    app = QApplication(sys.argv)
    ex = Example()
#     ex.show()
    sys.exit(app.exec_())

单元测试：-

    import unittest
import same_label


class Test(unittest.TestCase):


    def setUp(self):
        ex = same_label.Example()


    def tearDown(self):
        pass


    def testName(self):
        pass


if __name__ == "__main__":
    #import sys;sys.argv = ['', 'Test.testName']
    unittest.main()

错误：-

QWidget: Must construct a QApplication before a QWidget

Answer 1

必须在创建任何小部件之前创建 QApplication，因为它处理事件循环

import unittest
import same_label
import sys

from PyQt5.QtWidgets import QApplication

app = QApplication(sys.argv)


class Test(unittest.TestCase):
    def setUp(self):
        ex = same_label.Example()

    def tearDown(self):
        pass

    def testName(self):
        pass


if __name__ == "__main__":
    #import sys;sys.argv = ['', 'Test.testName']
    unittest.main()

在以下链接中有一个示例： http: //johnnado.com/pyqt-qtest-example/，另一个选择是使用pytest-qt包