根据最近的多边形 acrpy 填充点字段

如何解决根据最近的多边形 acrpy 填充点字段

我需要根据最近的多边形 Name 字段填充点 Name 字段。我尝试使用 arcpy.analysis.GenerateNearTable 创建内存表，但它没有保存我需要的任何字段。我如何才能做到这一点并避免创建新图层和删除连接？

near_result = arcpy.analysis.GenerateNearTable(
       fc,fc1,r'in_memory\neartable','','LOCATION','NO_ANGLE','CLOSEST')

rows = arcpy.SearchCursor(near_result)
for row in rows:
    arcpy.CalculateField_management(fc,"Name","PYTHON_9.3","")

我也试过这个更新光标，但它只在点在多边形中时才有效。

with arcpy.da.UpdateCursor(fc,['SHAPE@','Name']) as ucursor:
    for update_row in ucursor:
        with arcpy.da.SearchCursor(fc1,'Name']) as scursor:
            for search_row in scursor:
                if update_row[0].within(search_row[0]):
                    update_row[1] = search_row[1]
                    ucursor.updateRow(update_row)

解决方法

我不想这么说，但您最好进行空间连接，但您可以在内存中创建要素类，然后立即将其删除。以下是我在类似情况下所做的：

target_fc = 'Points'
join_fc = 'Polygons'
target_fld = 'Name'
join_fld = 'Name'
search_radius = '100 feet'

sj = 'memory\\temp_sj'
if arcpy.Exists(sj):
    arcpy.management.Delete(sj)

arcpy.analysis.SpatialJoin(target_fc,join_fc,sj,'JOIN_ONE_TO_ONE','KEEP_COMMON',None,'CLOSEST',search_radius)

# Create dictionary with key=point object id,val=nearest polygon name
# Note,TARGET_FID is always the field for OBJECTID of target feature
#     prior to the spatial join
# I sometimes like to do a dry run in Pro to make sure the field I want
#     is actually called "Polygons.Name" and the spatial join is doing the right thing
point_dict = {}
with arcpy.da.SearchCursor(sj,['TARGET_FID',f'{join_fc}.{join_fld}']) as cursor:
    for row in cursor:
        oid = row[0]
        polygon_name = row[1]
        point_dict[oid] = polygon_name

arcpy.management.Delete(sj)  # Delete temp spatial join feature class

# only update features that had a polygon within the search radius
# technically the WHERE clause is redundant bc we specified "KEEP_COMMON"
#     in the spatial join.
sql_where = f"OBJECTID IN {str(tuple(point_dict))}"
with arcpy.da.UpdateCursor(target_fc,['OBJECTID',target_fld],sql_where) as cursor:
    for row in cursor:
        oid = row[0]
        row[1] = point_dict[oid]  # Polygon name
        cursor.updateRow(row)

如果您的数据集有多个记录，这将比使用嵌套游标快得多。