https://community.esri.com/t5/python-questions/arcgis-pro-m-value-tools-is-quot-set-direction-as/m-p/1282833#M67518 <P>Think you'll have to do it manually with a cursor and extracting the m from the point.&nbsp; Stealing a post from <A href="https://gis.stackexchange.com/questions/142052/alter-the-m-values-of-an-existing-route" target="_blank" rel="noopener">SO</A></P><LI-CODE lang="python">lyr = r"C:\Users\...\Default.gdb\TEST_ROUTE" fields = ['SHAPE@'] with arcpy.da.UpdateCursor(lyr, fields) as cursor: for row in cursor: partslist = [] partlist = [] array = None feat = row[0] partnum = 0 # Count the number of points in the current multipart feature partcount = feat.partCount pntcount = 0 # Enter while loop for each part in the feature (if a singlepart feature # this will occur only once) # while partnum &lt; partcount: part = feat.getPart(partnum) pnt = part.next() # Enter while loop for each vertex # while pnt: pntcount += 1 if not numpy.isnan(pnt.M): partlist.append(arcpy.Point(pnt.X, pnt.Y, pnt.Z, pnt.M / 1000)) pnt = part.next() # If pnt is null, either the part is finished or there is an # interior ring # if not pnt: pnt = part.next() partslist.append(arcpy.Array(partlist)) array = arcpy.Array(partslist) partlist = [] partnum += 1 polylinefeat = arcpy.Polyline(array) row[0] = polylinefeat cursor.updateRow(row)</LI-CODE><P>&nbsp;</P> Wed, 26 Apr 2023 14:44:07 GMT Anonymous User 2023-04-26T14:44:07Z https://community.esri.com/t5/python-questions/arcgis-pro-m-value-tools-is-quot-set-direction-as/m-p/1281040#M67468 <P>ArcGIS Pro has tools for working with M values. Are these functionalities available in arcpy?</P><P><span class="lia-inline-image-display-wrapper lia-image-align-inline" image-alt="m-value-tools-arcgis-pro.png" style="width: 326px;"><img src="https://community.esri.com/t5/image/serverpage/image-id/68654i88B13EB7E06221EB/image-size/large?v=v2&amp;px=999" role="button" title="m-value-tools-arcgis-pro.png" alt="m-value-tools-arcgis-pro.png" /></span></P> Thu, 20 Apr 2023 21:10:12 GMT https://community.esri.com/t5/python-questions/arcgis-pro-m-value-tools-is-quot-set-direction-as/m-p/1281040#M67468 DanielWebb 2023-04-20T21:10:12Z https://community.esri.com/t5/python-questions/arcgis-pro-m-value-tools-is-quot-set-direction-as/m-p/1282833#M67518 <P>Think you'll have to do it manually with a cursor and extracting the m from the point.&nbsp; Stealing a post from <A href="https://gis.stackexchange.com/questions/142052/alter-the-m-values-of-an-existing-route" target="_blank" rel="noopener">SO</A></P><LI-CODE lang="python">lyr = r"C:\Users\...\Default.gdb\TEST_ROUTE" fields = ['SHAPE@'] with arcpy.da.UpdateCursor(lyr, fields) as cursor: for row in cursor: partslist = [] partlist = [] array = None feat = row[0] partnum = 0 # Count the number of points in the current multipart feature partcount = feat.partCount pntcount = 0 # Enter while loop for each part in the feature (if a singlepart feature # this will occur only once) # while partnum &lt; partcount: part = feat.getPart(partnum) pnt = part.next() # Enter while loop for each vertex # while pnt: pntcount += 1 if not numpy.isnan(pnt.M): partlist.append(arcpy.Point(pnt.X, pnt.Y, pnt.Z, pnt.M / 1000)) pnt = part.next() # If pnt is null, either the part is finished or there is an # interior ring # if not pnt: pnt = part.next() partslist.append(arcpy.Array(partlist)) array = arcpy.Array(partslist) partlist = [] partnum += 1 polylinefeat = arcpy.Polyline(array) row[0] = polylinefeat cursor.updateRow(row)</LI-CODE><P>&nbsp;</P> Wed, 26 Apr 2023 14:44:07 GMT https://community.esri.com/t5/python-questions/arcgis-pro-m-value-tools-is-quot-set-direction-as/m-p/1282833#M67518 Anonymous User 2023-04-26T14:44:07Z https://community.esri.com/t5/python-questions/arcgis-pro-m-value-tools-is-quot-set-direction-as/m-p/1287902#M67615 <P>This seems to do what I want. Thank you!</P> Wed, 10 May 2023 18:56:37 GMT https://community.esri.com/t5/python-questions/arcgis-pro-m-value-tools-is-quot-set-direction-as/m-p/1287902#M67615 DanielWebb 2023-05-10T18:56:37Z