Getting error in finding spatial reference of shapefile

Question

I am working on Ubuntu, when I tried to read spatial reference of shapefile it give me this error.

spatialRef = layer.GetSpatialRef().ExportToProj4()

Traceback (most recent call last):

File "< stdin>", line 1, in < module>

AttributeError: 'NoneType' object has no attribute 'GetSpatialRef'

Help me to remove it

• YoLecomte: Maybe an upper case issue.... getSpatialRef instead of GetSpatialRef???
• PADAMNABH ELECTRONICS: still getting same error spatialRef = layer.getSpatialRef() Traceback (most recent call last): File "<stdin>", line 1, in <module> AttributeError: 'NoneType' object has no attribute 'getSpatialRef'
• YoLecomte: What is layer??
• PADAMNABH ELECTRONICS: www2.census.gov/geo/tiger/TIGER2009/tl_2009_us_state.zip (state polygon layer)
• YoLecomte: So layer variable contain a None type object. Try to get a reference to a layer before and it should work

Answer 1

I don't understand your problem. You need a layer or a geometry or an EPSG code

With the www2.census.gov/geo/tiger//TIGER2009/tl_2009_us_state.zip shapefile

from osgeo import ogr
file = ogr.Open('tl_2009_us_state.shp') # from www2.census.gov/geo/tiger/TIGER2009/tl_2009_us_state.zip 
layer = file.GetLayer()
spatialRef = layer.GetSpatialRef()
spatialRef.ExportToProj4()
'+proj=longlat +datum=NAD83 +no_defs '
spatialRef.AutoIdentifyEPSG()
spatialRef.GetAuthorityCode(None)
'4269'

With a geometry

feature = layer.GetNextFeature()
geometry = feature.GetGeometryRef()
spatialRef = geometry.GetSpatialReference()
spatialRef.ExportToProj4()
'+proj=longlat +datum=NAD83 +no_defs '

With an EPSG code (EPSG:4269)

spatialRef = osr.SpatialReference()
spatialRef.ImportFromEPSG(4269)
spatialRef.ExportToProj4()
'+proj=longlat +ellps=GRS80 +towgs84=0,0,0,0,0,0,0 +no_defs '

Answer 2

This is how I read the spatial reference of a shapefile.

from osgeo import ogr
file = ogr.Open("C:\file_path\file_name.shp")
layer = file.GetLayer()
spatial_ref= layer.GetSpatialRef()
print spatial_ref

To get the individual spatial reference attributes:

spatial_attr = spatial_ref.GetAttrValue('projcs')
print spatial_attr

This will output the projection coordination system, e.g. "WGS_1984_UTM_Zone_38N".

Answer 3

AttributeError: 'NoneType' object has no attribute 'GetSpatialRef'

The error message means, that your layer variable is empty. Check the way you obtain it.