（3）ArcPy：创建点线面要素及添加字段

使用ArcPy创建常用的要素文件时（shapefile），如、点、线面要素，其创建步骤基本相同。线、面要素与点要素创建的不同在于，点要素使用单个点坐标创建，线和面则是将一组点放入一个数组中，使用数组来创建线或者面。下面展示创建要素的基本步骤：
均为在PyCharm中进行

## 创建要素的基本步骤：
# 1.输入数据
# 2.定义空间参考
# 3.确定创建要素的路径、名称
# 4.创建要素类
# 5.创建要素字段
# 6.创建游标
# 7.创建点，遍历所有数据
# 8.新建要素、新建行
# 9.将新建的行写入游标中

点、线、面要素的创建如上所述。下面展示点线面要素创建的python代码以及相应的解释：
1.点要素的创建

#coding:utf-8
import arcpy
points=[[113.12345,34.3654],[113.12365,34.65894],[113.12389,34.6547]]

sp=arcpy.SpatialReference(4326)
path="H:pyStudydata_points" #输出创建文件的路径
filename="testPoint.shp"      #所创建文件的名称
fc=arcpy.CreateFeatureclass_management(path,filename,"POINT","","","",sp) #创建要素类
arcpy.AddField_management(fc,"FIDX","TEXT",50) #创建字段，即属性表中的字段名
arcpy.AddField_management(fc,"X","TEXT",50)
arcpy.AddField_management(fc,"Y","TEXT",50)
cursor=arcpy.InsertCursor(fc) #创建游标

index=0
for pt in points:
    point=arcpy.Point()
    point.X=pt[0]
    point.Y=pt[1]
    row=cursor.newRow()
    row.shape=point
    row.FIDX=index #将字段数据写入行中
    row.X=pt[0]
    row.Y=pt[1]
    cursor.insertRow(row)
    index+=1
print "Finished!"
print "创建成功!"


##创建多点，即多个点为一条记录
pointArray=[
            [[113.12345,34.3654],[113.12365,34.65894],[113.12389,34.6547]],
            [[113.1235,34.3654],[113.12365,34.6894],[113.2389,34.6547]],
            [[113.12345,34.654],[113.365,34.6894],[113.9,34.6547]],
           ]
sp=arcpy.SpatialReference(4326)
path="H:pyStudydata_points"
filename="testMultiPoints"
fc=arcpy.CreateFeatureclass_management(path,filename,"MULTIPOINT","","","",sp)
arcpy.AddField_management(fc,"FIDn","TEXT",50)
cursor=arcpy.InsertCursor(fc)

index=0
for coord in pointArray:
    array=arcpy.Array()
    for pt in coord:
        point=arcpy.Point()
        point.X=pt[0]
        point.Y=pt[1]
        array.add(point)
    multipoint=arcpy.Multipoint(array)

    row=cursor.newRow()
    row.shape=multipoint
    row.FIDn=index
    cursor.insertRow(row)
    index+=1
print "创建多点完成！"#创建单点

2.线要素的创建

###创建线要素
polylinePts=[
            [[113.12345,34.3654],[113.12365,34.65894],[113.12389,34.6547]],
            [[113.1235,34.3654],[113.12365,34.6894],[113.2389,34.6547]],
            ] #每组有三个点，每组为一条线段
sp=arcpy.SpatialReference(4326)
path="H:pyStudydata_polylines"
filename="test_polylines.shp"
fc=arcpy.CreateFeatureclass_management(path,filename,"POLYLINE","","","",sp)
arcpy.AddField_management(fc,"polyline","TEXT",50)
cursor=arcpy.InsertCursor(fc)

for coord in polylinePts:
    array=arcpy.Array()
    for pt in coord:
        point=arcpy.Point()
        point.X=pt[0]
        point.Y=pt[1]
        array.add(point)
    polyline=arcpy.Polyline(array)
    row=cursor.newRow()
    row.shape=polyline
    row.polyline="***123"
    cursor.insertRow(row)
print "创建线要素完成！"

3.面要素的创建

###创建面要素
polygonPts=[
             [[113.12345,34.3654],[114.12365,34.65894],[113.12389,34.6547]],
             [[113.1235,34.3654],[113.12365,35.6894],[113.2389,34.6547]],
           ] #每组三个点，三个点组成一个面
sp=arcpy.SpatialReference(4326)
path="H:pyStudydata_polygon"
filename="test_polygons.shp"
fc=arcpy.CreateFeatureclass_management(path,filename,"POLYGON","","","",sp)
arcpy.AddField_management(fc,"Polygon","TEXT",50)
cursor=arcpy.InsertCursor(fc)

for coord in polygonPts:
    array = arcpy.Array()
    for pt in coord:
        point=arcpy.Point()
        point.X=pt[0]
        point.Y=pt[1]
        array.add(point)
    polygon=arcpy.Polygon(array)
    row=cursor.newRow()
    row.shape=polygon
    row.Polygon="Polygon"
    cursor.insertRow(row)
print "面要素创建完成！"