python - QProcess 将参数传递给 python 脚本

Question

from PIL import Image
def porcentaje(path):

    im = Image.open(path, "r")
    im.show()
    width, height = im.size
    type = im.mode
    format = im.format
    pixels=im.getdata()
    n = len(pixels)
   im=im.load()
   nblack = 0
   noblack=0

   for pixel in pixels:
       if pixel < 50:
           nblack += 1
       else:
           noblack+=1

porcentajefinal=(nblack*100)/n
print(porcentajefinal)
return(porcentajefinal)

(porcentaje(path))

mainwindow.cpp (QT Creator)

void MainWindow::on_pushButton_2_clicked()
{

    QString path = QFileDialog::getOpenFileName(this,
            tr("All Files (*)"));
     qDebug()<<path;

     QDir dir1("D:/QTCProjects/prueba");
     QFile file1("D:/QTCProjects/prueba/2_1.py");
     QString script1 = "D:/QTCProjects/prueba/2_1.py";
     QFile file2(script1);

     qDebug() << dir1.exists() << file1.exists() << file2.exists();
       //  these all result in true, true true
     QProcess *myProcess = new QProcess();
     myProcess->start("python.exe D:/QTCProjects/prueba/2_1.py" );
     myProcess->waitForFinished(-1);

      qDebug() << "myProcess:" << myProcess->readAll(); }

这个 python 需要一个名为 path 的变量来运行，我在 qtcreator 中使用 Qstring 路径获取这个变量，我如何用 Qpr​​ocess 给 python 这个变量。

Answer 1

如果要通过终端将参数传递给脚本，则使用以下结构:

python.exe /path/of/your_script.py arg1 arg2 ... argn

然后要获取参数，我们必须使用 sys.argv，它是一个存储以下内容的列表:

['/path/of/your_script.py', 'arg1', 'arg2', ..., 'argn']

因此在您的情况下，您应该通过 sys.argv[1] 获取参数:

2_1.py

from PIL import Image
import sys

def porcentaje(path):

    im = Image.open(path, "r")
    im.show()
    width, height = im.size
    type = im.mode
    format = im.format
    pixels=im.getdata()
    n = len(pixels)
    im=im.load()
    nblack = 0
    noblack=0
    for pixel in pixels:
        if pixel < 50:
            nblack += 1
        else:
            noblack+=1

    porcentajefinal=(nblack*100.0)/n
    print(porcentajefinal)
    return(porcentajefinal)

path = sys.argv[1]
porcentaje(path)

在Qt这边，python.exe是主程序，其他参数都是实参，所以你的代码必须有如下结构:

void MainWindow::on_pushButton_2_clicked()
{
    QString path = QFileDialog::getOpenFileName(this, "All Files (*)");
    qDebug()<<path;
    if(!path.isEmpty()){
        QDir dir("D:/QTCProjects/prueba");
        QFileInfo info(dir, "2_1.py");
        qDebug() << dir.exists() << info.exists();
        QProcess process;
        process.start("python.exe", QStringList()<< info.absoluteFilePath() << path);
        process.waitForFinished(-1);
        qDebug() << "myProcess:" << process.readAll();
    }
}