因使用太多 for 循环、if 和 else 语句而感到困惑

Question

我正在为地理信息系统软件 QGIS 开发一个插件。我创建了一个 QTableWidget 并希望从中提取值：

问题是，我使用了很多 for 循环和 if else 语句，直到最后几行，它们似乎工作正常。我现在似乎无法遵循逻辑，因为行 print constraint_name 仅打印出最后一个值 "Example_2"。我可以将其从相应的 else 语句中取出，然后它将正确打印所有值，但我需要将其设置在一个条件内：

qTable = self.dockwidget.tableWidget  # QTableWidget
example_group = root.findGroup('Main group')  # Group containing sub groups
all_items = []
gis_map = QgsMapLayerRegistry.instance().mapLayersByName( "Map" )[0]  # Layer map in QGIS
idx = gis_map.fieldNameIndex("Rank")  # Get "Rank" attribute field from gis_map
for row in range(qTable.rowCount()):
    for col in [0]:  # For first column "Constraint name"
        constraint_item = qTable.item(row, col)                            
        constraint_name = str(constraint_item.text())
    for col in [1]:  # For second column "Rank"
        item = qTable.item(row, col)
        item_string = str(item.text())
        all_items.append(item_string)
        for group in example_group.children():  # Search for specific group
            if group.name() == "Sub group":
                if len(set(all_items)) == 1:  # If all items are the same
                    # If "Rank" field exists in layer map
                    if idx == -1:
                        print 'success'
                    else: 
                        print 'fail'                        
                else:
                    if idx == -1:
                        print constraint_name
                    else:
                        print 'fail'

有没有办法整理它并仍然得到正确的结果？

Answer 1

我衷心感谢指导我找到更有效解决方案的评论者，这是有效的工作代码（我相信它可以进一步完善）：

qTable = self.dockwidget.tableWidget
example_group = root.findGroup('Main group')
all_items = []
gis_map = QgsMapLayerRegistry.instance().mapLayersByName( "Map" )[0]
idx = gis_map.fieldNameIndex("Rank")
for row in range(qTable.rowCount()):
    constraint_item = qTable.item(row, 0)                            
    constraint_name = str(constraint_item.text())
    item = qTable.item(row, 1)
    item_string = str(item.text())
    all_items.append(item_string)
    for group in example_group.children():
        if group.name() == "Sub group":
            if idx == -1:
                if len(set(all_items)) == 1:
                    print 'success'
                else: 
                    print 'fail'                        
            else:
                print constraint_name

因使用太多 for 循环、if 和 else 语句而感到困惑

Confused by using too many for loops, if and else statements

python

qgis