Subtracting attributes of different records based on common attribute

Discussion created by khayman on Jun 25, 2014
Latest reply on Jun 25, 2014 by eibenm
I'm not sure if this is the right place to put this question.  If not, please let me know.

I am trying to find the angle between adjacent lines in a single layer.  I plan to accomplish this by subtracting the incidence angle of one line from that of its adjacent line. The lines come from polylines split at vertices, so the start coordinates of one line exactly match the end coordinates of another line.

I have a field with the incidence angle for each line, a field with the begin xy of the line, and a field with the end xy of the line.  I am trying to figure out how to have a script loop through the table, find the line whose beginningxy matches the endxy of the current line, and subtract the angles.  I am not very familiar with Python so I would greatly appreciate guidance.