游标遵循图层/表格视图定义查询和选择。游标对象仅包含任一地理处理工具在操作期间将使用到的行。

insertRow

插入游标用于创建并插入新行。基本的处理流程是在要插入行的游标对象上使用 newRow 方法。新的行对象包含在表中找到的所有字段，并且在使用 insertRow 插入行之前可以为行中的字段分配值。

import arcpy# Create insert cursor for table#rows = arcpy.InsertCursor("D:/St_Johns/data.gdb/roads_lut")x = 1# Create 25 new rows. Set the initial row ID and distance values#while x <= 25:    row = rows.newRow()    row.rowid = x    row.distance = 100    rows.insertRow(row)    x = x + 1

updateRow

updateRow 方法用于对更新游标当前所在位置的行进行更新。从游标对象提取行对象后，可以根据需要对行进行修改，然后调用 updateRow 传入修改后的行。

import arcpy# Create update cursor for feature class#rows = arcpy.UpdateCursor("D:/St_Johns/data.gdb/roads")for row in rows:# Update the field used in buffer so the distance is based on the road#   type. Road type is either 1, 2, 3, or 4. Distance is in meters.#    row.buffer_distance = row.road_type * 100    rows.updateRow(row)

deleteRow

deleteRow 方法用于删除更新游标当前所在位置的行。提取行对象后，可在游标上调用 deleteRow 删除行。

import arcpy# Create update cursor for feature class#rows = arcpy.UpdateCursor("D:/St_Johns/data.gdb/roads")for row in rows:    # Delete all rows that have a roads type of 4    if row.road_type == 4:        rows.deleteRow(row)

import arcpyfrom arcpy import envimport osenv.overwriteOutput = 1env.workspace = arcpy.GetParameterAsText(0)# List the polygon feature classes#fcs = arcpy.ListFeatureClasses("*","polygon")# Loop through the results.#for fc in fcs:   # Get the ObjectID field   #   desc = arcpy.Describe(env.workspace + os.sep + fc)   OIDFieldName = desc.OIDFieldName   # Create lookup table name   #   if fc.endswith(".shp"):      tab = fc.replace(".", "_lut.")   else:      tab = fc + "_lut"   # Create lookup table and add fields   #   arcpy.CreateTable_management(env.workspace, tab)   arcpy.AddField_management(tab,"id","long")   arcpy.AddField_management(tab,"dist","long")   # Open insert cursor on new lookup table   #   tabcur = arcpy.InsertCursor(env.workspace + os.sep + tab)   # Open search cursor on feature class   #   featcur = arcpy.SearchCursor(env.workspace + os.sep + fc)   # Loop through the rows in the feature class   #   for f_row in featcur:       # Create a new row for the lookup table and set its ID to be the       #  same as the feature OID and set the distance to 100.       #       t_row = tabcur.newRow()       t_row.id = f_row.getValue(OIDFieldName)       t_row.dist = 100       # Insert the row into the lookup table and get the next row       #  from the feature class       #       tabcur.insertRow(t_row)

import arcpy# Create update cursor for feature class#try:    # The variables row and rows are initially set to None, so that they    #  can be deleted in the finally block regardless of where (or if)    #  script fails.    #    row, rows = None, None    rows = arcpy.UpdateCursor("D:/St_Johns/data.mdb/roads")    # Update the field used in buffer so the distance is based on the     #   road type. Road type is either 1, 2, 3 or 4. Distance is in meters.    #    for row in rows:        row.buffer_distance = row.road_type * 100        rows.updateRow(row)except:    if not arcpy.GetMessages() == "":        arcpy.AddMessage(arcpy.GetMessages(2))finally:    # Regardless of whether the script succeeds or not, delete     #  the row and cursor    #    if row:        del row    if rows:        del rows