python - SWITCH_SELECTION 不适用于 SelectLayerByLocation_management

Question

 import arcpy,sys
 sdeConn = r"Database Connections\\Test.sde"
 muniLoc = "Municipalities"
 luLoc = "Land_Use"
 tempLoc = "tempMuniLuRatio"
 arcpy.env.workspace = sdeConn

 try:
    print "MakeFeatureLayer_management lu_lyr"
    arcpy.MakeFeatureLayer_management(luLoc, "lu_lyr") 
    prematchcount = int(arcpy.GetCount_management("lu_lyr").getOutput(0)) 
    print "MakeFeatureLayer_management muni_lyr"
    #arcpy.MakeFeatureLayer_management(muniLoc, "muni_lyr") 
    print "SelectLayerByLocation_management COMPLETELY_WITHIN"
    arcpy.SelectLayerByLocation_management("lu_lyr", "COMPLETELY_CONTAINS",muniLoc,"","SWITCH_SELECTION")
     postmatchcount = int(arcpy.GetCount_management("lu_lyr").getOutput(0)) 
    if prematchcount == postmatchcount:
        print "SelectLayerByLocation_management DID NOT WORK"
    else:
        print "SelectLayerByLocation_management LOOKS GOOD"
        if arcpy.Exists(tempLoc):
            print "Delete_management "
            arcpy.Delete_management(tempLoc)
        print "CopyFeatures_management "
        arcpy.CopyFeatures_management('lu_lyr',tempLoc)
 except Exception:
    e = sys.exc_info()[1]
    print(e.args[0])

所以我添加

if prematchcount == postmatchcount: 

查看SWITCH_SELECTION是否有效。

每次它返回与源特征class相同的结果。

我的代码中是否遗漏了任何内容？

Answer 1

TL;DR

更改此:

arcpy.SelectLayerByLocation_management("lu_lyr", "COMPLETELY_CONTAINS",muniLoc,"","SWITCH_SELECTION")

对此:

arcpy.SelectLayerByLocation_management("lu_lyr", "COMPLETELY_CONTAINS",muniLoc)
arcpy.SelectLayerByLocation_management("lu_lyr", None, None, "", "SWITCH_SELECTION")

---

详细信息

GetCount_management 和 SelectLayerByLocation_management 正在按文档说明工作。

来自Get Count :

If a selection is defined on the input, the count of the selected rows is returned.

来自Select Layer By Location :

SWITCH_SELECTION —Switches the selection. All records that were selected are removed from the selection, and all records that were not selected are added to the selection. The select_features and overlap_type parameters are ignored when this option is selected.

让我解释一下您的代码在做什么以及为什么它是正确的。

arcpy.MakeFeatureLayer_management(luLoc, "lu_lyr")

您创建了一个没有选择的要素图层。假设 Land_Use 要素类包含 42 个要素。

prematchcount = int(arcpy.GetCount_management("lu_lyr").getOutput(0))

由于 lu_lyr 上没有定义选择，因此要素类中的所有要素都会被计数，并且 prematchcount 现在等于 42。

arcpy.SelectLayerByLocation_management("lu_lyr", "COMPLETELY_CONTAINS",muniLoc,"","SWITCH_SELECTION")

由于您使用的是 SWITCH_SELECTION，因此 COMPLETELY_CONTAINS 和 muniLoc 将被忽略，并且只需切换选择即可。在此调用之前，选择了零个功能。此调用会切换选择，以便选择所有 42 个功能。

postmatchcount = int(arcpy.GetCount_management("lu_lyr").getOutput(0))

由于在 lu_lyr 上定义了选择，因此仅对选定的功能进行计数。上一行选择了全部 42 个特征，因此 postmatchcount 现在等于 42。

if prematchcount == postmatchcount:

确实。他们都是 42 岁。

您的修复取决于您想要做什么，但您没有说出来。我的猜测是，您想要选择 Land_Use 中不完全包含 Municipalities 中某个要素的所有要素，并将这些选定的要素复制到 tempMuniLuRatio。如果是这样，请进行此答案顶部描述的更改。如果没有，请编辑您的问题以解释您想要做什么。