Python

From Wildsong
Revision as of 22:44, 31 October 2006 by Brian Wilson (talk | contribs) (→‎ESRI)
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Brian's random notes on Python

Links

Quick links into the official docs

TUTORIAL http://docs.python.org/tut/tut.html

GENERAL http://docs.python.org/

STRINGS http://docs.python.org/lib/string-methods.html

http://diveintopython.org/

Geoprocessing

ESRI

This guy seems to have slogged through a lot of development with it and collected useful notes: http://www.ollivier.co.nz/support/python.shtm

I can add a new one to his list. I was getting error messages on setting gp.workspace = 'foo' where foo is a valid path. It's because the gp object was hanging around in pythonwin's memory. You should be able to say 'del gp' but I gave up and restarted pythonwin to fix it.

When working with ArcToolbox 9.1 and Python 2.1 I have been having lots of crashes in PythonWin. Using it on a computer with ActiveState 2.4.3 I have not been experiencing the same problems. I am going to try installing 2.4x without removing 2.1 so I can fall back on it... I followed the instructions above.

It still crashes. Oh joy. It does not even crash faster.

Open source

How about geoprocessing with OGR/GDAL? Will that do it for me?

Getting Python 2.4 and GDAL without disrupting the ESRI installation... See also Howard Butler's site.

Not good enough: FWtools installs a funky GUI called OpenEV_FW and a shell environment. It comes with python 2.3.4 which is old but better than ESRI's 2.1 It does NOT include the pythonwin IDE. How INCORNVENIENT!

23-Aug-2006 Python+OGR probably not worth messing with right now. From the OGR site: The Python API isn't really well documented at this time, but parallels the C/C++ APIs. The interface classes can be browsed in the pymod/ogr.py (simple features) and pymod/osr.py (coordinate systems) python modules. The pymod/samples/assemblepoly.py sample script is one demonstration of using the python API.