GIS 4048 - Module 5 Assignment: Working with Geometries

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Working with Geometries
The screenshot is a final product of a written script that created a TXT file writing the coordinates and object IDs for specific rivers (vertices) in a shapefile. The screenshot was taken from NotePad++ and consists of a total of 247 vertices. 

 Screen shot of final TXT file:





Flowchart:



Process Summary Notes:

During this week’s lab I had the most opportunity with the cursor and write( ) portion of the assignment. While trying to construct my code I noticed I was running into the same few errors every time I felt I made progress. Some of the errors I was getting in the IPython window were: 

“typeerror: 'point' object is not iterable”

“typeerror: 'row' object is not subscriptable”

After some guidance and explanation from the wonderful T.A. I realized my mistake. To correct the two errors above I had to correct my field values and my write statement. At the beginning on my script, I added my “fields”. For example, [field=’OID@’, ‘SHAPE@’, and ‘NAME’]. Without having my fields set my script had nothing to refer to, creating an error when trying to run.

Next, I did not realize I was grouping my X and Y coordinates separately. It is important to make sure the X and Y go together as one, because you cannot have one without the other. When you plot a point or coordinate you do not have just one, right?

Lastly, there was an error in my write( ) statement and print statement that was creating some headache. I was forgetting that I needed to set a string to everything I was calling for in my write and print statements. Specifically my error was when trying to write and print ‘NAME’ or for example, str(row[2]).  This is because ‘NAME’ has more than one word per each entry, so I added a string for success. I feel my biggest “ah ha” moment was when I realized that a string (str) is needed when a specified value has more than one entry and realizing my script only needed one print statement because it needs to run a one chunk.

As for references for completing this assignment, the most helpful script reference was from our Module 5 exercise on page 4, and this was a major contributor to our assignment script.

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