如何在布局管理器中的小部件之间添加所需的填充量？

作为一个选项：

'''
from PyQt6.QtCore import QSize, Qt
from PyQt6.QtWidgets import QApplication, QMainWindow, QWidget, QPushButton, QLabel, QVBoxLayout, QHBoxLayout, QFrame, QScrollArea, QSpacerItem, QSizePolicy
'''
import sys
from PyQt5.Qt import *
#? from style import StyleSheet


class SubWidget(QFrame):
    def __init__(self, label_text, button_text, parent_layout) -> None:
        super().__init__()
        self.setObjectName("sub_widget")
        self.parent_layout = parent_layout
        self.setFixedSize(320, 45)

        self.label = QLabel(label_text)
        self.button_delete = QPushButton(button_text)
        self.button_delete.clicked.connect(self.delete_widget)
        self.layout = QHBoxLayout(self)
        self.layout.addWidget(
            self.label, alignment=Qt.AlignmentFlag.AlignCenter)
        self.layout.addWidget(
            self.button_delete, 
            alignment=Qt.AlignmentFlag.AlignRight|Qt.AlignmentFlag.AlignRight)

    def delete_widget(self):
        self.deleteLater()
        

class MainWindow(QMainWindow):
    def __init__(self) -> None:
        super().__init__()
        self.setWindowTitle("MainWindow")
        self.setObjectName("main_window")
    
        central_widget = QWidget(self)
        central_widget.setObjectName("central_widget")
        self.setCentralWidget(central_widget)

        self.scroll_area = QScrollArea()
        self.scroll_area.setObjectName("scroll_area")
        self.scroll_area.setWidgetResizable(True)
        self.scroll_widget = QWidget()
        self.scroll_widget.setAutoFillBackground(True)
        self.scroll_widget.setStyleSheet("border-radius: 10px;")
        self.widget_layout = QVBoxLayout(self.scroll_widget)
        self.widget_layout.setContentsMargins(5, 5, 5, 0)

# +++ ------------------------------> v <-----------------------------
        self.widget_layout.setSpacing(5)                         # 15
        self.widget_layout.insertStretch(999, stretch = 1)       # +++

        self.scroll_area.setWidget(self.scroll_widget)

        create_label_btn = QPushButton("Create")
        create_label_btn.clicked.connect(self.create_label)

        self.main_layout = QVBoxLayout(central_widget)   
        self.main_layout.addWidget(self.scroll_area)               
        self.main_layout.addWidget(create_label_btn)
        
    def create_label(self) -> None:
        new_widget = SubWidget(f"New Label", "Delete", self.widget_layout)
# +++
        count = self.widget_layout.count() - 1                       # +++
# -----------------------> vvvvvvvvvvvv <---------------------------------        
        self.widget_layout.insertWidget(                             # +++
            count,                                                   # +++
            new_widget,                                              # +++
            alignment=Qt.AlignmentFlag.AlignCenter)                  # +++


StyleSheet = """
    #central_widget {            
        background-color: #5d7; 
        border-radius: 20px;  
    }
    #scroll_area {              
        background-color: #5f7;
        border-radius: 10px;  
    }
    #sub_widget {
        border: 2px solid #fff; 
        border-radius: 10px;
        background-color: #abc;  
    }
    QLabel {                        
        background-color: green;    
        color: #fff;
        border-radius: 10px;
    }
    QPushButton {
        background-color: gray;  
        border: none;
        padding: 5px;
        border-radius: 10px;           
    }
"""


if __name__ == "__main__":
    app = QApplication(sys.argv)
    app.setStyleSheet(StyleSheet)
    window = MainWindow()
    window.setFixedSize(QSize(350, 500))
    window.show()
    app.exec()