change expanding space of nested layouts in pyqt

I want to seperate the widgets of the mainwindow into 3 layouts and add them into a mainlayout the center layout contains a tablewidget and shoud have a bigger width then the left/right one. so far I did not found a way to use a grid layout and adjust each column width individualy.

therefore I tryed to use 3 vboxlayouts and insert them into an hboxlayout

what if read so far is that the widgets size are fixed so they expand at the same rate if stretched.

is there an easier way to make the center layout widht bigger with for example inserting an spacer without changing the SizePolicy of each widget ?

import sys

from PyQt5 import QtWidgets as qtw
from PyQt5 import QtCore as qtc
from PyQt5 import QtGui as qtg


class Stretchme(qtw.QWidget):
    def __init__(self):
        super().__init__()

        # # View
        table_widget = qtw.QTableWidget()


        # -----interface--widgets--------------------------#

        # -------- parameter_widgets------------#
        parameter_label = qtw.QLabel("Parameter")

        test_time_label = qtw.QLabel("Time")
        self.clocktime = qtw.QTimeEdit()
        test_date_label = qtw.QLabel("Date")
        self.date_time = qtw.QDateEdit()

        grob_fein_label = qtw.QLabel("Grobe")
        grob_fein_combo_box = qtw.QComboBox()


        vr_label = qtw.QLabel("Lame")
        self.vr_feuchte_input = qtw.QLineEdit()


        # leftvboxlayout
        left_vboxlayout = qtw.QVBoxLayout()

        left_vboxlayout.addStretch(1)

        left_vboxlayout.addWidget(test_time_label)
        left_vboxlayout.addWidget(self.clocktime)
        left_vboxlayout.addWidget(test_date_label)
        left_vboxlayout.addWidget(self.date_time)
        left_vboxlayout.addWidget(grob_fein_label)
        left_vboxlayout.addWidget(grob_fein_combo_box)
        left_vboxlayout.addWidget(vr_label)
        left_vboxlayout.addWidget(self.vr_feuchte_input)

        # centervboxlayout
        center_voboxlayout = qtw.QVBoxLayout()
        #
        # center_voboxlayout.addStretch()
        # center_voboxlayout.setStretchFactor()
        # center_voboxlayout.addSpacing()
        # center_voboxlayout.setStretchFactor()

        #
        # table_widget.setMinimumSize(90,80)

        center_voboxlayout.addWidget(table_widget)


        # righvobxlayout
        # buttons
        self.button_1 = qtw.QPushButton("Button 1")
        self.button_2 = qtw.QPushButton("Button 2")
        self.button_2 = qtw.QPushButton("Button 3")


        rightvboxlayout = qtw.QVBoxLayout()
        rightvboxlayout.addStretch(1)
        rightvboxlayout.addWidget(self.button_1)
        rightvboxlayout.addWidget(self.button_2)
        rightvboxlayout.addWidget(self.button_2)



        #
        #
        # Separador = qtw.QFrame()
        # # Separador.Shape(QFrame.HLine)
        # Separador.setFrameShape(qtw.QFrame.HLine)
        #
        # Separador.setSizePolicy(qtw.QSizePolicy.Minimum,qtw.QSizePolicy.Expanding)
        # Separador.setLineWidth(5)
        # # HPOUT1_layout = QVBoxLayout()
        # # HPOUT1_layout.addLayout(HPOUT1L_layout)
        # # HPOUT1_layout.addWidget(Separador)
        # # HPOUT1_layout.addLayout(HPOUT1R_layout)


        ## main layout
        self.qhboxlayout = qtw.QHBoxLayout()
        self.qhboxlayout.addLayout(left_vboxlayout)
        # self.qhboxlayout.addWidget(Separador)
        self.qhboxlayout.addLayout(center_voboxlayout)
        self.qhboxlayout.addLayout(rightvboxlayout)
        #
        # ### Main Grid

        # -------------------------------------------------- #
        selected_color = qtg.QColor(0,0,255)

        # self.setGeometry(300, 300, 1850, 950)
        self.setStyleSheet("background-color: {}")
        self.setLayout(self.qhboxlayout)

        self.show()


if __name__ == '__main__':
    app = qtw.QApplication(sys.argv)
    w = Stretchme()
    sys.exit(app.exec_())