Arcpy connecting points with lines using coordinates

Question

Based on another post, I wrote a Python script that reads coordinates, creates points, and then connects them. Here is the code:

import arcpy
in_rows = arcpy.SearchCursor(r"C:\Users\cchen\Documents\temp\test.gdb\linetest")
point = arcpy.Point()
array = arcpy.Array()
featureList = []
cursor = arcpy.InsertCursor(r"C:\Users\cchen\Documents\temp\test.gdb\newlines")
feat = cursor.newRow()
for in_row in in_rows:
 # Set X and Y for start and end points
 point.X = in_row.sx
 point.Y = in_row.sy
 array.add(point)
 point.X = in_row.ex
 point.Y = in_row.ey
 array.add(point) 
 # Create a Polyline object based on the array of points
 polyline = arcpy.Polyline(array)
 # Clear the array for future use
 array.removeAll()
 # Append to the list of Polyline objects
 featureList.append(polyline)
 # Insert the feature
 feat.shape = polyline
 cursor.insertRow(feat)
del feat
del cursor

It gives me this error message: Runtime error Traceback (most recent call last): File "", line 14, in File "c:\program files (x86)\arcgis\desktop10.4\arcpy\arcpy\arcobjects_base.py", line 89, in _set return setattr(self._arc_object, attr_name, cval(val)) RuntimeError: Point: Input value is not numeric

Since the field is numeric(double), I am confused on why this does not work.

• Vince: You need to create more than one Point (inside the loop), since this code just moves one point around and attempts to create a line with only one (repeating) vertex. You should use a DA cursor for an order of magnitude performance benefit, and the Polyline constructor shoild include a SpatialReference.
• PMK: try converting "in_row.sx", "in_row.sy","in_row.ex","in_row.ey" to float. i.e. float(in_row.sx). That error is probably becasue the ex,ey,sx, and sy values are strings.
• klewis: You might be able to use "XY to Line" to create your 2 point lines.

Answer 1

search cursor is declaring all fields by default so in_row is a list of field values. You would need to access the shape by index so I would expect an error, but that the attribute .sx exist is a little confusing, but can modify.

in_rows = arcpy.SearchCursor(r"C:\Users\cchen\Documents\temp\test.gdb\linetest",
 ["SHAPE@XY"])
for in_row in in_rows:
 x, y = in_row[0]
 print("{}, {}".format(x, y))

Then you would need to get at least two unique points into the array to successfully create a polyline.