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：

问题是，我使用了很多for循环和if else语句，这些语句直到最后几行才能正常工作。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＆＃34; Example_2＆＃34;。我可以从相应的else语句中取出它然后它会正确打印所有值，但我需要将它设置在一个条件中：

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'

有没有办法整理这个并仍能得到正确的结果？

Answer 1

我真诚地感谢那些指导我提供更高效解决方案的评论者，这里有正常工作的代码（我确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

通过使用太多的for循环，if和else语句来混淆

1 个答案: