用Arcpy读取shapefile

本文主要从两个部分介绍：
1. shapefile文件属性表的读取
2. shapefile内每个元素的坐标信息读取

---

属性表读取

分这几步走：
1. arcpy.ListFields函数解析shp文档所在路径，并返回列名数组
2. arcpy.da.SearchCursor读取列名下的属性表内容

inputLayer = 'C:\Users\Wu823\Desktop\data_test\starbucks.shp;'theFields = arcpy.ListFields(inFC)for Field in theFields:    FieldsArray.append(Field.aliasName)for row in arcpy.da.SearchCursor(inFC, FieldsArray):    print row

坐标信息读取

坐标信息也是通过arcpy.da.SearchCursor函数来获取。和上面不同的是，列名需要换成几何令牌
ArcGIS Manual上面的解释内容如下：

• SHAPE@XY —A tuple of the feature’s centroid x,y coordinates.
• SHAPE@TRUECENTROID —A tuple of the feature’s true centroid x,y coordinates.
• SHAPE@X —A double of the feature’s x-coordinate.
• SHAPE@Y —A double of the feature’s y-coordinate.
• SHAPE@Z —A double of the feature’s z-coordinate.
• SHAPE@M —A double of the feature’s m-value.
• SHAPE@JSON — The esri JSON string representing the geometry.
• SHAPE@WKB —The well-known binary (WKB) representation for OGC geometry. It provides a portable representation of a geometry value as a contiguous stream of bytes.
• SHAPE@WKT —The well-known text (WKT) representation for OGC geometry. It provides a portable representation of a geometry value as a text string.
• SHAPE@ —A geometry object for the feature.
• SHAPE@AREA —A double of the feature’s area.
• SHAPE@LENGTH —A double of the feature’s length.
• OID@ —The value of the ObjectID field.

我这里主要用到SHAPE@XY和SHAPE@两个令牌

• SHAPE@XY：返回几何要素的中心坐标
• SHAPE@：返回一整个几何要素

第一个很好理解，就是个二元数组。
第二个，整个几何要素。
几何要素包含点线面等。根据个人实际操作经验，几何要素其实就是多维数组。点是一维，面和线是三维（点->部分->记录）。searchCursor的返回值也确实如此。

# A list of features and coordinate pairsfeature_info = [[[1, 2], [2, 4], [3, 7]],                [[6, 8], [5, 7], [7, 2], [9, 5]]]for row in arcpy.da.SearchCursor(inFC, 'SHAPE@'):    for part in row:        for pnt in part:            print pnt.X            print pnt.Y

参考来源：http://pro.arcgis.com/en/pro-app/arcpy/get-started/reading-geometries.htm