[Reading a csv file and removing the lines that I won't be needing]

[appdev]

Hello guys,

I hope you're doing very well.
So I tried to read a csv file by displaying it in a QTableView.
However there are some lines that I won't to delete so here is what I tried to do

void MainWindow::on_actionOpen_triggered()
{
    auto filename=QFileDialog::getOpenFileName(this,"Open", QDir::rootPath(), "CSV File(*.csv)");
    if (filename.isEmpty()) {
        return;
    }
    QFile file(filename);
    if (!file.open(QIODevice::ReadOnly | QIODevice::Text)) {
        return;
    }
    QTextStream xin(&file);
    int ix = 0;
    while(!xin.atEnd()) {
        mModel->setRowCount(ix);
        auto line = xin.readLine();
        qDebug() << "line"<<line;
        auto values = line.split(";");
        qDebug() << "values" << values;
        const int colCount = values.size();
        mModel->setColumnCount(colCount);

        for (int jx = 0; jx< colCount; ++jx) {
           setValueAt(ix, jx, values.at(jx));
        }
       qDebug() << "values at jx" << values.at(3);
       if (values.at(3)!='5') { mModel->removeRow(ix);}
        ++ix;
    }
    file.close();
}

After displaying the whole csv file, I wanted to remove all the rows where the values of the third columns are different from '5' But that didn't work.

Can someone please help me ?
Thanks.

[JonB]

@appdev said in [Reading a csv file and removing the lines that I won't be needing]:

But that didn't work.

What didn't work? If you want to use removeRow() like you do

       if (values.at(3)!='5') { mModel->removeRow(ix);}
        ++ix;

you will not want to increment ix if you remove the row, put it in an else?

Or, make your decision about looking at column #3 before you commit to to adding the row in the first place?

[appdev]

@JonB Thank your for the quick reply,

What didn't work is that when i run my application and open the csv file, I get an empty file with 9 columns since my csv file contains 9 columns.

Okay so for the first solution, you mean that I should do like this:

 if (values.at(3)!='5') { mModel->removeRow(ix);}
      else {  ++ix; }

?
I tried it but it didn't work, it looks like the program isn't taking the if condition into consideration.
I thought about the second solution you suggested but the row removal seems to be less complicated.

[JonB]

@appdev
I really don't know what your issue is.

 if (values.at(3)!='5') { mModel->removeRow(ix);}
      else {  ++ix; }

Yes to the else.

You seem to me to have a logic problem with your initialisation of int ix = 0; followed by mModel->setRowCount(ix);. So you set 0 rows and then call setValueAt(0, ...). You need to think about what you are doing, and at a guess mModel->setRowCount(ix + 1);.

I thought about the second solution you suggested but the row removal seems to be less complicated.

If you think so, fine. Otherwise put your columns into values, check whether values.at(3)!='5', and only add the row with its column values after the check on that column instead of before.

[appdev]

@JonB Hello again, Thank you so much for your help.

Well, I ended up using the second solution your suggested and which is making the decision about looking at column #3 before adding rows and it worked.

Thank you again.