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Run python script in Qt

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  • N NotYourFan
    3 Jul 2019, 06:05

    i reinstalled python and checked the variables … all fine.
    And as i said, when i run the Script with cmd ( cmd -> python.exe "path/createJSON.py") it works perfect

    J Offline
    J Offline
    J.Hilk
    Moderators
    wrote on 3 Jul 2019, 06:07 last edited by
    #4

    @NotYourFan
    well, have you tried giving QProcess the absolute path to the python file, as you did in your cmd prompt ?


    Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


    Q: What's that?
    A: It's blue light.
    Q: What does it do?
    A: It turns blue.

    1 Reply Last reply
    2
    • N Offline
      N Offline
      NotYourFan
      wrote on 3 Jul 2019, 07:33 last edited by
      #5

      yes of coruse, like:

      void TestWindow::loadFile()
          QProcess p;
          QStringList params;
      
          params << "createJSON.py";
          p.start("C:/development/Python/Python37/python.exe", params);
          p.waitForFinished(-1);
          QString p_stdout = p.readAll();
      
      J 1 Reply Last reply 3 Jul 2019, 07:37
      0
      • N NotYourFan
        3 Jul 2019, 07:33

        yes of coruse, like:

        void TestWindow::loadFile()
            QProcess p;
            QStringList params;
        
            params << "createJSON.py";
            p.start("C:/development/Python/Python37/python.exe", params);
            p.waitForFinished(-1);
            QString p_stdout = p.readAll();
        
        J Offline
        J Offline
        J.Hilk
        Moderators
        wrote on 3 Jul 2019, 07:37 last edited by J.Hilk 7 Mar 2019, 07:37
        #6

        @NotYourFan said in Run python script in Qt:
        I actually meant the absolute path to

        createJSON.py

        I assume createJSON.py is inside your project folder and you start the program via QtCreator but, the created exe is not in your project folder -> so it can't find the python script


        Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


        Q: What's that?
        A: It's blue light.
        Q: What does it do?
        A: It turns blue.

        1 Reply Last reply
        1
        • N Offline
          N Offline
          NotYourFan
          wrote on 3 Jul 2019, 08:11 last edited by
          #7

          Sry @J-Hilk i missunderstood.

          But i try this also …

          like:

          void TestWindow::loadFile()
              QProcess p;
              QStringList params;
          
              params << "C:/development/Qt/ProjektXY/createJSON.py";
              p.start("C:/development/Python/Python37/python.exe", params);
              p.waitForFinished(-1);
              QString p_stdout = p.readAll();
          

          i´m desperately … i dont know what to do, i try everything.

          J 1 Reply Last reply 3 Jul 2019, 08:20
          0
          • N NotYourFan
            3 Jul 2019, 08:11

            Sry @J-Hilk i missunderstood.

            But i try this also …

            like:

            void TestWindow::loadFile()
                QProcess p;
                QStringList params;
            
                params << "C:/development/Qt/ProjektXY/createJSON.py";
                p.start("C:/development/Python/Python37/python.exe", params);
                p.waitForFinished(-1);
                QString p_stdout = p.readAll();
            

            i´m desperately … i dont know what to do, i try everything.

            J Offline
            J Offline
            J.Hilk
            Moderators
            wrote on 3 Jul 2019, 08:20 last edited by
            #8

            @NotYourFan since you're on windows, you're using the wrong path separator


            Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


            Q: What's that?
            A: It's blue light.
            Q: What does it do?
            A: It turns blue.

            J 1 Reply Last reply 3 Jul 2019, 10:35
            0
            • N Offline
              N Offline
              NotYourFan
              wrote on 3 Jul 2019, 08:22 last edited by
              #9

              @J-Hilk whats the Right path separator?

              J 1 Reply Last reply 3 Jul 2019, 08:25
              0
              • N NotYourFan
                3 Jul 2019, 08:22

                @J-Hilk whats the Right path separator?

                J Offline
                J Offline
                J.Hilk
                Moderators
                wrote on 3 Jul 2019, 08:25 last edited by J.Hilk 7 Mar 2019, 08:27
                #10

                @NotYourFan
                https://en.wikipedia.org/wiki/Filename#Reserved_characters_and_words


                backslash or probably double backslash


                Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                Q: What's that?
                A: It's blue light.
                Q: What does it do?
                A: It turns blue.

                1 Reply Last reply
                0
                • N Offline
                  N Offline
                  NotYourFan
                  wrote on 3 Jul 2019, 08:26 last edited by
                  #11
                  This post is deleted!
                  1 Reply Last reply
                  0
                  • N Offline
                    N Offline
                    NotYourFan
                    wrote on 3 Jul 2019, 08:29 last edited by
                    #12

                    okay, thx for your Suggestion.

                    void TestWindow::loadFile()
                        QProcess p;
                        QStringList params;
                    
                        params << "C:\\development\\Qt\\ProjektXY\\createJSON.py";
                        p.start("C:\\development\\Python\\Python37\\python.exe", params);
                        p.waitForFinished(-1);
                        QString p_stdout = p.readAll();
                    

                    i tried one time with Backslash and one time with double Backslash … same Problem.

                    1 Reply Last reply
                    0
                    • J J.Hilk
                      3 Jul 2019, 08:20

                      @NotYourFan since you're on windows, you're using the wrong path separator

                      J Offline
                      J Offline
                      jsulm
                      Lifetime Qt Champion
                      wrote on 3 Jul 2019, 10:35 last edited by
                      #13

                      @J.Hilk said in Run python script in Qt:

                      since you're on windows, you're using the wrong path separator

                      With Qt / should work on Windows as well, shouldn't it?

                      https://forum.qt.io/topic/113070/qt-code-of-conduct

                      J A 2 Replies Last reply 3 Jul 2019, 10:45
                      0
                      • J jsulm
                        3 Jul 2019, 10:35

                        @J.Hilk said in Run python script in Qt:

                        since you're on windows, you're using the wrong path separator

                        With Qt / should work on Windows as well, shouldn't it?

                        J Offline
                        J Offline
                        J.Hilk
                        Moderators
                        wrote on 3 Jul 2019, 10:45 last edited by
                        #14

                        @jsulm I'm unsure

                        usually yes, but in this case you're trying to start a System program from the OS. Until now, I've always only used it to start an external program, that I shipped with the other Qt installation and therefore was always at the same depth as the main executable or it was on a unix system...

                        @NotYourFan
                        have you seen this thread ?
                        https://stackoverflow.com/questions/15127047/qt-calling-external-python-script

                        It may help you


                        Be aware of the Qt Code of Conduct, when posting : https://forum.qt.io/topic/113070/qt-code-of-conduct


                        Q: What's that?
                        A: It's blue light.
                        Q: What does it do?
                        A: It turns blue.

                        A 1 Reply Last reply 3 Jul 2019, 10:47
                        0
                        • J jsulm
                          3 Jul 2019, 10:35

                          @J.Hilk said in Run python script in Qt:

                          since you're on windows, you're using the wrong path separator

                          With Qt / should work on Windows as well, shouldn't it?

                          A Offline
                          A Offline
                          aha_1980
                          Lifetime Qt Champion
                          wrote on 3 Jul 2019, 10:46 last edited by
                          #15

                          @jsulm

                          With Qt / should work on Windows as well, shouldn't it?

                          It is really important to use forward slashes for Qt functions, yes. However, the parameter for python (the path to the script) is not evaluated from Qt but from the python interpreter, so here backslashes might be needed.

                          That gives:

                          params << "C:\\development\\Qt\\ProjektXY\\createJSON.py";
                          p.start("C:/Development/Python/Python37/python.exe", params);
                          

                          Looks funny, though.

                          p.waitForFinished(-1); I would use a SLOT here.

                          And for testing: can you just try python -c 'print "Hello World"' first?

                          Qt has to stay free or it will die.

                          1 Reply Last reply
                          3
                          • J J.Hilk
                            3 Jul 2019, 10:45

                            @jsulm I'm unsure

                            usually yes, but in this case you're trying to start a System program from the OS. Until now, I've always only used it to start an external program, that I shipped with the other Qt installation and therefore was always at the same depth as the main executable or it was on a unix system...

                            @NotYourFan
                            have you seen this thread ?
                            https://stackoverflow.com/questions/15127047/qt-calling-external-python-script

                            It may help you

                            A Offline
                            A Offline
                            aha_1980
                            Lifetime Qt Champion
                            wrote on 3 Jul 2019, 10:47 last edited by
                            #16

                            @J.Hilk said in Run python script in Qt:

                            usually yes, but in this case you're trying to start a System program from the OS

                            As said, the path for QProcess should work with forward slash. The path for the parameter (the script) probably not.

                            Qt has to stay free or it will die.

                            1 Reply Last reply
                            0
                            • N Offline
                              N Offline
                              NotYourFan
                              wrote on 3 Jul 2019, 11:03 last edited by
                              #17

                              @J-Hilk thank you for the stackoverflow link, i've seen it and try it.
                              @aha_1980 i test python -c 'print "Hello World"' --> i get Nothing.

                              A 1 Reply Last reply 3 Jul 2019, 11:32
                              0
                              • N NotYourFan
                                3 Jul 2019, 11:03

                                @J-Hilk thank you for the stackoverflow link, i've seen it and try it.
                                @aha_1980 i test python -c 'print "Hello World"' --> i get Nothing.

                                A Offline
                                A Offline
                                aha_1980
                                Lifetime Qt Champion
                                wrote on 3 Jul 2019, 11:32 last edited by
                                #18

                                @NotYourFan said in Run python script in Qt:

                                @aha_1980 i test python -c 'print "Hello World"' --> i get Nothing.

                                How did you test it?

                                Qt has to stay free or it will die.

                                1 Reply Last reply
                                0
                                • N Offline
                                  N Offline
                                  NotYourFan
                                  wrote on 3 Jul 2019, 11:58 last edited by
                                  #19

                                  put python -c 'print "Hello World"' in p.start

                                  P J J 3 Replies Last reply 3 Jul 2019, 12:29
                                  0
                                  • N NotYourFan
                                    3 Jul 2019, 11:58

                                    put python -c 'print "Hello World"' in p.start

                                    P Offline
                                    P Offline
                                    Pablo J. Rogina
                                    wrote on 3 Jul 2019, 12:29 last edited by
                                    #20

                                    @NotYourFan just in case, you may want to use Python embedded in your Qt application...

                                    Upvote the answer(s) that helped you solve the issue
                                    Use "Topic Tools" button to mark your post as Solved
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                                    • N NotYourFan
                                      3 Jul 2019, 11:58

                                      put python -c 'print "Hello World"' in p.start

                                      J Offline
                                      J Offline
                                      jsulm
                                      Lifetime Qt Champion
                                      wrote on 3 Jul 2019, 13:54 last edited by
                                      #21

                                      @NotYourFan It doesn't work like this. You have to put the command as first parameter to start() and all parameters for the command as parameter list.

                                      https://forum.qt.io/topic/113070/qt-code-of-conduct

                                      Gojir4G 1 Reply Last reply 3 Jul 2019, 14:08
                                      1
                                      • J jsulm
                                        3 Jul 2019, 13:54

                                        @NotYourFan It doesn't work like this. You have to put the command as first parameter to start() and all parameters for the command as parameter list.

                                        Gojir4G Offline
                                        Gojir4G Offline
                                        Gojir4
                                        wrote on 3 Jul 2019, 14:08 last edited by
                                        #22

                                        @jsulm Are you sure about that ?
                                        from Qt Doc:

                                        QProcess process;
                                        process.start("del /s *.txt");
                                        
                                        1 Reply Last reply
                                        0
                                        • N Offline
                                          N Offline
                                          NotYourFan
                                          wrote on 4 Jul 2019, 05:37 last edited by NotYourFan 7 Apr 2019, 05:38
                                          #23

                                          @jsulm i readed in the Qt Doc.
                                          @Gojir4 you are right.
                                          @Pablo-J-Rogina thx for your Suggestion … but i should / want to do it with QProcess …

                                          1 Reply Last reply
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