[Python知识库]python GDAL实现按属性选择图层（等同于arcpy的SelectLayerByAttribute_management）

?不废话了，直接上封装好的函数

# -*- coding: utf-8 -*-

import os
from osgeo import ogr, osr, gdal

gdal.SetConfigOption("GDAL_FILENAME_IS_UTF8", "YES")
gdal.SetConfigOption("SHAPE_ENCODING", "UTF8")

#gdal.SetConfigOption("GDAL_FILENAME_IS_UTF8", "NO")
#gdal.SetConfigOption( "SHAPE_ENCODING", "GBK")

def Add_Field(input_lyr, field_name, ogr_field_type):
    """
    Add a field to a layer using the following ogr field types:
    0 = ogr.OFTInteger
    1 = ogr.OFTIntegerList
    2 = ogr.OFTReal
    3 = ogr.OFTRealList
    4 = ogr.OFTString
    5 = ogr.OFTStringList
    6 = ogr.OFTWideString
    7 = ogr.OFTWideStringList
    8 = ogr.OFTBinary
    9 = ogr.OFTDate
    10 = ogr.OFTTime
    11 = ogr.OFTDateTime
    """

    # List fields
    fields_ls = List_Fields(input_lyr)

    # Check if field exist
    if field_name in fields_ls:
        raise Exception('Field: "{0}" already exists'.format(field_name))

    # Create field
    inp_field = ogr.FieldDefn(field_name, ogr_field_type)
    input_lyr.CreateField(inp_field)

    return inp_field

def SelectByAttribute(InShp, Field, FieldType, attriNames, coor, outShp):
    ds = ogr.Open(InShp,0)
    if ds is None:
    	raise OSError('Could not open {}'.format(InShp))
    ly_count = ds.GetLayerCount()
    layer = ds.GetLayer(0)
    lyInfo = layer.GetLayerDefn()
    driver = ogr.GetDriverByName("ESRI Shapefile") 
    if os.access(outShp, os.F_OK ): #如文件已存在，则删除
        driver.DeleteDataSource(outShp) 
    ds_new = driver.CreateDataSource(outShp) #创建shp文件
    spatialref_new = osr.SpatialReference()
    CoorDict = {'WGS84':4326, 'BeiJing54': 4214, 'XIAN80':4610, 'CGCS2000': 4490}
    spatialref_new.ImportFromEPSG(CoorDict[coor])
    geomtype = ogr.wkbPolygon 

    layer_new = ds_new.CreateLayer(outShp[:-4], srs=spatialref_new, geom_type=geomtype,) #创建图层 for fd in fieldlist: #将字段列表写入图层
    layer_new.CreateField(ogr.FieldDefn(Field, FieldType))

    features = []
    for i in range(layer.GetFeatureCount()):
        feature = layer.GetFeature(i)
        geom_polygon = feature.GetGeometryRef()
        name = feature.GetField(Field)
        feat = ogr.Feature(layer_new.GetLayerDefn())

        if name in attriNames:
            feat.SetGeometry(geom_polygon)
            feat.SetField(Field, name)
            features.append(feat)

    for f in features:
        layer_new.CreateFeature(f)
    ds.Destroy()
    ds_new.Destroy()


if __name__ == "__main__":
    shp = 'D:/csdn/seg_new_v2/data/20220315/test.shp'
    filename_new = "D:/csdn/seg_new_v2/data/20220315/temp.shp"

    SelectByAttribute(shp, 'ff', ogr.OFTString, ['att'], 'CGCS2000', filename_new)

?说明：

# gdal.SetConfigOption("GDAL_FILENAME_IS_UTF8", "YES")
# gdal.SetConfigOption("SHAPE_ENCODING", "UTF8")

gdal.SetConfigOption("GDAL_FILENAME_IS_UTF8", "NO")
gdal.SetConfigOption( "SHAPE_ENCODING", "GBK")

这里下面两句是为了尝试处理字段写入属性值时中文乱码的问题，但是没有用，解决人麻烦在评论区留言。

参数说明：

SelectByAttribute(shp, 'ff', ogr.OFTString, ['att'], 'CGCS2000', filename_new)

1.??shp 就是需要被选择属性的矢量文件

2. 'ff'? 在这个字段里选择具有 ['att']属性的矢量

3. gr.OFTString? 就是你字段的类型，后面在新的图层里创建字段的时候也要参考，类型的种类在Add_Field有给出来，不确定的话对照一下

4.? ['att']? 属性列表，就是你要选择哪些属性的矢量出来，这里可以给多个

5. 'CGCS2000'? 矢量对应的坐标系，代码里给了对应的编码号

6.??filename_new 输出矢量，会自动创建