Pulling numbers from ASCII filename not working

Bengt Richter bokr at oz.net
Wed Jan 25 09:13:14 CET 2006

On 24 Jan 2006 10:44:32 -0800, "IamIan" <iansan at gmail.com> wrote:

>I searched the archives but couldn't find anyone else with this
>problem. Basically I'm grabbing all ASCII files in a directory and
>doing geoprocessing on them. I need to calculate a z-factor based on
>the latitude of the ASCII file being worked on, which is in the
>filename. If I type in the code manually it works and reads the
>latitude value from the ASCII filename, but when run within ArcGIS it
>crashes when it gets to int(LatString). Isnumber() returned false for
>Latitude as well. Is there something different about reading values
>from an ASCII filename?
Aren't you curious as to what the value of LatString was that failed?
Don't you know how to find out?

>import sys, os, win32com.client, string, gc
># Get a list of ASCII files in the workspace for ASCII To Raster
>filenames = os.listdir(gp.workspace)
>filenames = [filename.lower()
>for filename in filenames
>if (filename[-4:].lower() == ".asc" and filename[0] != "-" )]
indentation of the above two lines would improve readability

>for filename in filenames:
I would try print repr(filename) here, to see what you are dealing with
>        # For each ASCII file, create Hillshade.
>        # account for latitude by computing Z units using radians
>        Latitude = filename[1:3]
>        LatString = str(Latitude)
you probably won't need a print repr(LatString) here if you see the above print
>        LatInt = int(LatString)
>        radians = LatInt * 0.0174532925
>        zFactor = 1/(113200 * (cos(radians)))
BTW, capitalizing the first letter of python variable names is counter to usual convention.

Bengt Richter

More information about the Python-list mailing list