SubPCallTest.py

from pydm import Display
from PyQt5.QtGui import QStandardItem
from PyQt5.QtWidgets import (QWidgetItem, QCheckBox, QPushButton, QLineEdit,
                             QGroupBox, QHBoxLayout, QMessageBox, QWidget,
                             QLabel, QFrame, QComboBox, QRadioButton)
from os import path
import subprocess
import sys
from matplotlib.backends.backend_qt5agg import FigureCanvasQTAgg
from matplotlib.figure import Figure
import FFt_math

lastPath=''


class MplCanvas(FigureCanvasQTAgg):
# MPLCanvas is the class for the 'canvas' that plots are drawn on and then mapped to the ui
# They are Figure format described in matplotlib 2.2 documentation

    def __init__(self, parent=None, width=5, height=4, dpi=100):
        fig = Figure(figsize=(width, height), dpi=dpi, tight_layout="true")
        self.axes = fig.add_subplot(111)
        super(MplCanvas, self).__init__(fig)



class MicDisp(Display):

    def __init__(self, parent=None, args=None, ui_filename="FFT_test2.ui"):
        super(MicDisp, self).__init__(parent=parent, args=args, ui_filename=ui_filename)
        self.pathHere = path.dirname(sys.modules[self.__module__].__file__)
        def getPath(fileName):
            return path.join(self.pathHere, fileName)
        self.show()
        # brings the display to the front
        self.raise_()
        # gives the display focus
        self.activateWindow()
        self.ui.AcqProg.setText("Test of printing output from subprocess  line by line")

        self.ui.StrtBut.clicked.connect(self.subCall)  # call function setGOVal when strtBut is pressed
        self.ui.AcqProg.setText("Select 1 CM and 1 cavity at a time for commissioning. \nLimit plotted waveforms to 30 sec.")    


    def subCall(self):    
        try:
            cmd=['python','-u','/home/user/tutorial/GitDir/Microphonics/Testy2.py']            
            process = subprocess.Popen(cmd, stdout=subprocess.PIPE, stderr=subprocess.PIPE, bufsize=1, shell=False)
            while True:
                output = process.stdout.readline().decode()
                if output == '' and process.poll() is not None:
                    break
                if output !='':
                    print(output)
                    self.ui.AcqProg.setText(output)
        
            return_code = process.poll()
            if return_code==0:
        #                self.ui.AcqProg.setText("Test run completed successfully")
                print("Test run completed sucessfully")
        
            if return_code !=0:
        #        print(err)
                e = subprocess.CalledProcessError(return_code, cmd)
        #                    e.stdout, e.stderr = err
        #                self.ui.AcqProg.setText("Call to microphonics script failed \n"+str(e))
                print("Call returned non-zero value")
             
        except:
#            self.ui.AcqProg.setText("try failed \n")
            print("try failed")