使用pyshp处理shapfile

在平时的数据处理中，经常会遇到将字符串或JSON格式数据转成空间数据的需求，使用ArcGIS Engine 或者shapelib单独写个应用程序比较麻烦，需要开发环境。编译，调试等等。那么使用python 直接操作shapefile 是一个比较好的选择。

pyshp 下载地址：

https://code.google.com/p/pyshp/

pyshp的使用比较简单

1.下载pyshp，将其放到python的根目录下（当然也可以通过设置path等方式来引用）

2.import shapefile

3.对shapefile进行操作

Reading Points in Shapes

>>> import shapefile
>>> sf = shapefile.Reader("shapefiles/blockgroups")
>>> shapes = sf.shapes()
>>> # Read the bounding box from the 4th shape
>>> shapes[3].bbox
[-122.485792, 37.786931000000003, -122.446285, 37.811019000000002]
>>>#  Read the 8th point in the 4th shape
>>> shapes[3].points[7]
[-122.471063, 37.787402999999998]
Reading Database Attributes

>>> # Read the field descriptors for the database file
>>> sf.fields
[("DeletionFlag", "C", 1, 0), ["AREA", "N", 18, 5], 
... ["BKG_KEY", "C", 12, 0], ["POP1990", "N", 9, 0], ["POP90_SQMI", "N", 10, 1], 
... ["HOUSEHOLDS", "N", 9, 0], 
... ["MALES", "N", 9, 0], ["FEMALES", "N", 9, 0]]
>>> # Read the 2nd and 3rd field values of the 4th database record
>>> sf.records[3][1:3]
['060750601001', 4715]
Writing Shapefiles

>>> import shapefile
>>> # Make a point shapefile
>>> w = shapefile.Writer(shapefile.POINT)
>>> w.point(90.3, 30)
>>> w.point(92, 40)
>>> w.point(-122.4, 30)
>>> w.point(-90, 35.1)
>>> w.field('FIRST_FLD')
>>> w.field('SECOND_FLD','C','40')
>>> w.record('First','Point')
>>> w.record('Second','Point')
>>> w.record('Third','Point')
>>> w.record('Fourth','Point')
>>> w.save('shapefiles/test/point')
>>> # Create a polygon shapefile
>>> w = shapefile.Writer(shapefile.POLYGON)
>>> w.poly(parts=[[[1,5],[5,5],[5,1],[3,3],[1,1]]])
>>> w.field('FIRST_FLD','C','40')
>>> w.field('SECOND_FLD','C','40')
>>> w.record('First','Polygon')
>>> w.save('shapefiles/test/polygon')