在主线程以外的线程中没有给出自动堆栈跟踪

时间:2015-04-07 17:09:07

标签: python multithreading pydev xlrd

我有一个相当大的程序,它从excel文件加载一些数据并填充表单,由于文件的大小,这可能需要很长时间,所以我一直在将加载函数移动到一个单独的线程上,唯一的问题出于某种原因,在这个新线程中,每当发生错误时,我都没有在控制台中获得自动堆栈跟踪。它一直在默默地失败,这让调试成为一种真正的痛苦。

我在eclipse中使用pydev,我编写了以下测试用例以确保一切正常。

    from PyQt4 import QtCore

class OtherThread(QtCore.QThread):


    def __init__(self):
        super(OtherThread, self).__init__()

    def run(self):
        try:
            print(1/0)
        except Exception as e:
            print("exception caught in other thread: \n{0}".format(e))

class MainThread():

    def __init__(self):
        self.otherThread = OtherThread()

    def run(self):
        try:
            print(1/0)
        except Exception as e:
            print("exception caught in main thread: \n{0}".format(e))

        self.otherThread.run()

def main():
    mainThread = MainThread()

    mainThread.run()

if __name__ == '__main__':
    main()

当我运行这个时,两个异常都被正确捕获,当我在胎面对象中注释掉try块时它也工作得很好,我得到了我预期的堆栈跟踪。我真的不知道发生了什么。有什么我可以做的导致这种行为?

以下是我正在处理的程序的代码。

    def run(self):
        print("excel thread running")

        workbook = xlrd.open_workbook(self.path)
        worksheet = workbook.sheet_by_name('PNA Form')
# 
        currentRow = 13 # start grabbing pna data
        numRowStart = currentRow
        newPartCol= 0
        oldPartCol = 10
        descriptionCol = 2
# 
        numberOfRows = worksheet.nrows - 1
#     
        print("number of rows = {0}".format(numberOfRows))
        PNA = []
#         
        current_color = False
        while (currentRow < numberOfRows):

            print("about to parse excel rows")
            newPartCell = int(worksheet.cell(currentRow,newPartCol).value)
            oldPartCell = int(worksheet.cell(currentRow,oldPartCol).value)
            descriptionCell =  QtCore.QString(worksheet.cell(currentRow,descriptionCol).value)

            print("excel rows parsed: {0}, {1}, {2}, {3}".format(oldPartCell,newPartCell,descriptionCell,current_color))

            print("running line excel row {0}: {1}".format(currentRow, str(descriptionCell)))
            if not self.isStrikethrough(currentRow,0): #make sure the line does not have strike through
                #self.guiHandel.BOMVal.addPNARow(oldPN = oldPartCell, newPN = newPartCell, disc = descriptionCell)
                print("about to emit pna row tracker for {0}".format(descriptionCell))
                self.addPNARowTracker.emit(oldPartCell,newPartCell,descriptionCell)
                print("thread still running after pna row tracker emit")

            if (oldPartCell != "" and not self.isStrikethrough(currentRow,0)):
                PNA.append((num(oldPartCell),num(newPartCell)))
                current_color = not current_color
                #self.guiHandel.pnaVerticalLayoutScroll.addWidget(PNACell(oldPartCell,newPartCell,descriptionCell,color = current_color))
                print("about to emit addPNARow: {0}, {1}, {2}, {3}".format(oldPartCell,newPartCell,descriptionCell,current_color))
                self.addPNARow.emit(oldPartCell,newPartCell,descriptionCell,current_color)
                #self.guiHandel.widgetStack.append(PNACell(oldPartCell,newPartCell,descriptionCell,color = current_color))
                print("thread still running after add pna row emit")

            currentRow += 1

            #self.guiHandel.pbar.setValue(int(100*(currentRow-13)/numberOfRows))
            print("currentRow =",currentRow)
            self.updateProgress.emit(int(100*(currentRow-numRowStart)/(numberOfRows-numRowStart)))

        print(PNA)
        self.done.emit()

这是失败时的控制台输出。

slot add pna row tracker called
running is about to return
about to emit addPNARow: 28458820, 28489881, INST CSTR-ASM,DIESEL,KM,UP,GAT, False
thread still running after add pna row emit
('currentRow =', 29slot add pna row called)

about to parse excel rows
Added addPNARow: 28458820, 28489881, INST CSTR-ASM,DIESEL,KM,UP,GAT, False
excel progress update called ------- progress = 20

当通过调试器运行时,它会在此行停止:

newPartCell = int(worksheet.cell(currentRow,newPartCol).value)

我尝试将它包装在try块中,但它从未遇到异常。它试图读取的单元格是空白的。

这里发生了什么?任何想法都将不胜感激。

1 个答案:

答案 0 :(得分:0)

回答此处的问题:error in pyqt qthread not printed

基本上你需要手动封装QThread对象的整个run方法,然后手动将错误重新抛出到stderr