I have this sample file shown in the picture 1 below. it is a sample data set of a phone survey of drivers. I am trying to find out when those drivers started to drive.

My main goal is to build a loop to go through the rows and compare each row for each unique trip id and to check between those rows when the X (dbX field) and the Y (dbY field) have changed. In my example (Picture 1) I have only two unique id trips - 55,56 but in my main data set i have alot more:

This is what I am trying to achieve in my goal data set:

  1. First row in goal data set (see picture two) will be based on: For example in picture 1 - the X and Y values in the first row changes from OBJECTID =6, when those values change I want to delete all previous rows until row 5.

    You can see an example of what I am trying to accomplish in picture 2.

  2. Next values Until last rows - For this values, I want to keep the first row where X and Y values changed and delete all values of the same X and Y untill the last row before the next X,Y changes again. to make this step clear I want to keep only rows with OBJECTID = 6 AND 13 and (picture 2)

Keep in my mind there are some Unique rows that Won't have more rows with the same X and Y like the row with OBJECTID = 78.

  1. Last row - at end of each unique id I want to keep only the first row that is diffrent from the previous row in terms of x and Y : for example in picture 1 I want to keep only OBJECTID = 149 and delete OBJECTID =1 150 AND 151

Initial Data set picture 1:

initial data set

This is the code I started writing but I think I am not on the right track

fcVertex ="Copy_Points_with_id_north_to_center_sample_55_57_copy"
fieldsvertex = ["dbX","dbY","Trip_ID","TimeStamp"]

with arcpy.da.UpdateCursor(fcVertex,fieldsvertex,sql_clause=(None, 'ORDER BY Trip_ID ASC ; ORDER BY TimeStamp ASC')) as deleteCursorfixtime:
for row1 in deleteCursorfixtime:
    for row2 in deleteCursorfixtime:
        if row1[2] == row2[2]:
            if row1[0]== row2[0] and row1[1] == row2[1]:
                 if row1[3] != row2[3]:

Goal Data set picture 2:

Goal data set

closed as unclear what you're asking by PolyGeo Sep 17 '16 at 0:02

Please clarify your specific problem or add additional details to highlight exactly what you need. As it's currently written, it’s hard to tell exactly what you're asking. See the How to Ask page for help clarifying this question. If this question can be reworded to fit the rules in the help center, please edit the question.

  • 1
    I've never tried, but I'm pretty sure that you can't iterate twice over the same feature class at the same time. Instead, you would want to go through once and build a dictionary that tracks the first and last features associated with an XY pair; from that determine which features will be preserved. Then iterate again deleting the necessary features. – Tom Jun 30 '16 at 14:32

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