Python：OSError：[Errno 9]尝试写入csv时发生错误的文件描述符

Question

我是编程的初学者，我尽力解决了这个错误。在下面的代码中，我尝试仅将文件名写入一次（在第7行中），以便向.csv文件中写入内容，以使代码更具可持续性。

但是使用下面的代码，我收到“发生错误的文件描述符”错误。我已经发现发生错误是因为.csv文件可能过早关闭。我不知道为什么，因为我没有在任何地方调用close（）。作为一种解决方法，我可以在代码中的所有位置将变量数据更改为“ NewFile.csv”。

我真的很感谢您在这里帮助我改善编程。

感谢您的帮助！

import sys
import csv
from qtpy import QtWidgets
from UI.mainwindow import Ui_MainWindow

#Dateiname/-pfad an Variable vergeben
data = "NewFile.csv"

app = QtWidgets.QApplication(sys.argv)

class MainWindow(QtWidgets.QMainWindow):

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

        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)
        self.setWindowTitle("Studentenverwaltung")

        self.ui.NewButton.clicked.connect(self.onNewButtonClick)
        self.loadTable(data)
        self.ui.SaveButton.clicked.connect(self.onSaveButtonClick)

    def loadTable(self, filename):
        self.ui.tableWidget.setRowCount(0)

        with open(filename, "r", newline="") as file:
            filereader = csv.reader(file, delimiter=";", quotechar='"')

            for row in filereader:
                first = row[0]
                last = row[1]
                subject = row[2]
                print(first + " " + last)

                newRow = self.ui.tableWidget.rowCount()

                self.ui.tableWidget.insertRow(newRow)
                self.ui.tableWidget.setItem(newRow, 0, QtWidgets.QTableWidgetItem(first))
                self.ui.tableWidget.setItem(newRow, 1, QtWidgets.QTableWidgetItem(last))
                self.ui.tableWidget.setItem(newRow, 2, QtWidgets.QTableWidgetItem(subject))

    def onSaveButtonClick(self, data):
        with open(data, "w", encoding="utf-8") as file:
            filewriter = csv.writer(file, delimiter=";", quotechar='"')

            totalRows = self.ui.tableWidget.rowCount()
            totalColumns = self.ui.tableWidget.columnCount()

            for row in range(totalRows):
                rowdata = []
                for column in range(totalColumns):
                    item = self.ui.tableWidget.item(row, column)
                    if item is not None:
                        rowdata.append(item.text())
                    else:
                        rowdata.append('')
                filewriter.writerow(rowdata)
                print(rowdata)

    def onNewButtonClick(self):
        newRow = self.ui.tableWidget.rowCount()
        self.ui.tableWidget.insertRow(newRow)
        self.ui.tableWidget.setItem(newRow, 0, QtWidgets.QTableWidgetItem(""))
        self.ui.tableWidget.setItem(newRow, 1, QtWidgets.QTableWidgetItem(""))
        self.ui.tableWidget.setItem(newRow, 2, QtWidgets.QTableWidgetItem(""))

        # Cursor auf neue Zelle setzen
        editingCell = self.ui.tableWidget.item(newRow, 0)
        self.ui.tableWidget.editItem(editingCell)

window = MainWindow()
window.show()

sys.exit(app.exec_())

错误消息：

OSError: [Errno 9] Bad file descriptor

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/User/Desktop/Coding/Python/PyQt/main.py", line 57, in onSaveButtonClick
    print(rowdata)
OSError: [Errno 9] Bad file descriptor

Process finished with exit code 134 (interrupted by signal 6: SIGABRT)

Answer 1

从data的参数列表中删除onSaveButtonClick参数。

    def onSaveButtonClick(self):

当Qt调用该函数时，它不会将文件名作为参数传递。您要为此使用全局变量，并声明一个参数以使之隐蔽。