topic Re: How to read a shapefile in Python Questions

How to read a shapefile

irinivozinaki — Tue, 09 Oct 2012 15:37:15 GMT

Hi

I am a really new python user and I need to read a shapefile named "hpq0"
I have tried the following:

import shapefile
sf = shapefile.Reader("shapefiles/hpq0.shp")

but nothing happens. Obviously in this way the path to find the shapefile "hpq.shp" is not defined.
Is there any procedure for reading shapefiles except from the one described in this:
http://pypi.python.org/pypi/pyshp/#reading-shapefiles

Thank you very much in advance!!!

Re: How to read a shapefile

ChristopherThompson — Tue, 09 Oct 2012 15:41:54 GMT

I'm not sure what you mean by 'read' the shapefile.. are you trying to get at the values in the attribute table? gather the geometry, or do something else?

Re: How to read a shapefile

DanPatterson_Retired — Tue, 09 Oct 2012 16:04:27 GMT

Read up on Cursors in the online help, specifically Searchcursors
http://help.arcgis.com/en/arcgisdesktop/10.0/help/index.html#//000v00000039000000

Re: How to read a shapefile

irinivozinaki — Tue, 09 Oct 2012 18:43:03 GMT

Yes I am trying to read the attribute table records and then I would like to insert these values in specific equations according to several scenarios.

Re: How to read a shapefile

ChristopherThompson — Tue, 09 Oct 2012 19:53:59 GMT

Dan's suggestions about looking at Search Cursors is valuable, also look at the tools for working with tables and table views. If you need to work through a table, fitting values from fields into formulae and then updating other fields in the same or another table look up the help topics on Update and Insert Cursors as well. Those are probably the key things for what you want to do. Reading and writing geometries are a bit different though still operate well using cursors.

Re: How to read a shapefile

irinivozinaki — Wed, 10 Oct 2012 04:40:56 GMT

Thank you very much for your help...I hope that I will manage it!
Have a nice day!

Re: How to read a shapefile

irinivozinaki — Wed, 10 Oct 2012 09:26:12 GMT

Me again!

I manage it!!! I can read the data in the columns of a polygon shapefile. But I have one more question.
Is it possible reading the columns data in the attribute table of a point shapefile?
Thank you!

Re: How to read a shapefile

ChristopherThompson — Wed, 10 Oct 2012 10:38:46 GMT

absolutely.. in fact, you should be able to use the same methods with your point file as with the polygon.