由于使用太多for循环、if和too语句而感到困惑

Question

我正在为GIS软件QGIS开发一个插件。我创建了一个QTableWidget并希望从中提取值：

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问题是，我使用了很多for循环和if else语句，直到最后几行为止，这些语句看起来都很好。我现在似乎无法遵循逻辑，因为行print constraint_name只输出最后一个值"Example_2“。我可以从它对应的else语句中取出它，然后它将正确地打印所有值，但是我需要在一个条件中设置它：

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'   

有没有办法把这件事整理一下，然后得到正确的结果呢？

Answer 1

我衷心感谢那些指导我找到一个更有效的解决方案的评论员，下面是工作代码(我相信它还可以进一步完善)：

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