Find below some code changed based on your comment and data provided.
- each route starts and feature with lowest segment ID
- will generate list of features that need to be flipped and a list of the order of the segments in the route
def main():
import arcpy
fc = r'C:\GeoNet\RoadDirection2\test.gdb\roads_m'
fld_name = 'RouteName'
fld_id = 'Segment_ID'
tolerance = 10
sr = arcpy.Describe(fc).spatialReference
dct_routes = {}
dct_seg_id_oid = {}
dct_oid_seg_id = {}
flds = ('OID@', 'SHAPE@', fld_name, fld_id)
with arcpy.da.SearchCursor(fc, flds) as curs:
for row in curs:
dct_data = {}
oid = row[0]
polyline = row[1]
route_name = row[2]
seg_id = row[3]
dct_seg_id_oid[seg_id] = oid
dct_oid_seg_id[oid] = seg_id
if route_name in dct_routes:
dct_data = dct_routes[route_name]
dct_data[oid] = [polyline, seg_id]
else:
dct_data[oid] = [polyline, seg_id]
dct_routes[route_name] = dct_data
dct_start_seg_id = {}
for route_name, dct_data in sorted(dct_routes.items()):
seg_ids = [s[1] for p,s in dct_data.items()]
dct_start_seg_id[route_name] = min(seg_ids)
lst_flip_oid = []
lst_candidates_todo = []
lst_multi_candidates = []
dct_route_order = {}
for route_name, seg_id in sorted(dct_start_seg_id.items()):
route_order = [seg_id]
print "trace:", route_name, " starting @", seg_id
dct_data = dct_routes[route_name]
dct_start_pnts = CreateDictionaryStartOrEndPoints(dct_data, "start")
dct_end_pnts = CreateDictionaryStartOrEndPoints(dct_data, "end")
oid = dct_seg_id_oid[seg_id]
start_pnt = dct_start_pnts[oid]
end_pnt = dct_end_pnts[oid]
lst_processed = [oid]
lst_todo = [o for o, lst in dct_data.items() if o != oid]
while len(lst_todo) > 0:
print "lst_processed:", lst_processed
oid_cand_end, start_end_end, dist_from_end = GetCandidate(end_pnt, dct_start_pnts, dct_end_pnts, lst_todo, tolerance)
print " - GetCandidate 1:", oid_cand_end, start_end_end, dist_from_end
oid_cand_start, start_end_start, dist_from_start = GetCandidate(start_pnt, dct_start_pnts, dct_end_pnts, lst_todo, tolerance)
print " - GetCandidate 2:", oid_cand_start, start_end_start, dist_from_start
if dist_from_start == 9999 and dist_from_end == 9999:
print" - no candidates!"
lst_candidates_todo.extend(lst_todo)
lst_todo = []
oid_found = None
elif dist_from_start == dist_from_end:
print " - two candidates with same score, error!"
lst_multi_candidates.append([oid_cand_end, oid_cand_start])
lst_candidates_todo.extend(lst_todo)
lst_todo = []
oid_found = None
elif dist_from_start < dist_from_end:
print " - candidate is at start of line, requires flip of current oid"
if start_end_start == "end":
print " - current start connects to candidate end, also candidate need to be flipped"
print " - adding candidate oid ", oid_cand_start, " to flip list"
lst_flip_oid.append(oid_cand_start)
if not oid in lst_flip_oid:
lst_flip_oid.append(oid)
print " - adding current oid ", oid, " to flip list"
oid_found = oid_cand_start
else:
if start_end_end== "end":
print " - current end connects to candidate end, candidate need to be flipped"
lst_flip_oid.append(oid_cand_end)
print " - adding candidate oid ", oid_cand_end, " to flip list"
oid_found = oid_cand_end
if oid_found != None:
start_pnt = dct_start_pnts[oid_found]
end_pnt = dct_end_pnts[oid_found]
lst_processed.append(oid_found)
route_order.append(dct_oid_seg_id[oid_found])
lst_todo.remove(oid_found)
oid = oid_found
print "lst_todo", lst_todo
print "lst_flip_oid", lst_flip_oid
dct_route_order[route_name] = route_order
print
print "lst_flip_oid :", sorted(lst_flip_oid)
print "lst_candidates_todo :", sorted(lst_candidates_todo)
print "lst_multi_candidates:", lst_multi_candidates
for route_name, route_order in sorted(dct_route_order.items()):
print " - Route:", route_name, " seg id order:", route_order
def GetCandidate(end_pnt, dct_start_pnts, dct_end_pnts, lst_todo, tolerance):
dist_min = 9999
oid_min = None
type_min = None
for oid, pnt in dct_start_pnts.items():
if oid in lst_todo:
dist = GetDistance(end_pnt.X, end_pnt.Y, pnt.X, pnt.Y)
if dist < tolerance:
if dist < dist_min:
dist_min = dist
oid_min = oid
type_min = "start"
for oid, pnt in dct_end_pnts.items():
if oid in lst_todo:
dist = GetDistance(end_pnt.X, end_pnt.Y, pnt.X, pnt.Y)
if dist < tolerance:
if dist < dist_min:
dist_min = dist
oid_min = oid
type_min = "end"
return oid_min, type_min, dist_min
def GetDistance(x1, y1, x2, y2):
import math
return math.hypot(x2-x1, y2-y1)
def CreateDictionaryStartOrEndPoints(dct_data, start_or_end):
dct_pnts = {}
for oid, lst in dct_data.items():
polyline = lst[0]
if start_or_end == "start":
dct_pnts[oid] = polyline.firstPoint
else:
dct_pnts[oid] = polyline.lastPoint
return dct_pnts
if __name__ == '__main__':
main()
Will yield:
trace: A starting @ 1
lst_processed: [1]
- GetCandidate 1: 2 end 0.0
- GetCandidate 2: None None 9999
- current end connects to candidate end, candidate need to be flipped
- adding candidate oid 2 to flip list
lst_todo [3]
lst_flip_oid [2]
lst_processed: [1, 2]
- GetCandidate 1: None None 9999
- GetCandidate 2: 3 start 0.0
- candidate is at start of line, requires flip of current oid
lst_todo []
lst_flip_oid [2]
trace: B starting @ 4
lst_processed: [4]
- GetCandidate 1: 5 start 0.0
- GetCandidate 2: None None 9999
lst_todo [6]
lst_flip_oid [2]
lst_processed: [4, 5]
- GetCandidate 1: 6 end 0.0
- GetCandidate 2: None None 9999
- current end connects to candidate end, candidate need to be flipped
- adding candidate oid 6 to flip list
lst_todo []
lst_flip_oid [2, 6]
trace: C starting @ 7
lst_processed: [10]
- GetCandidate 1: None None 9999
- GetCandidate 2: 8 start 0.0
- candidate is at start of line, requires flip of current oid
- adding current oid 10 to flip list
lst_todo [9, 7]
lst_flip_oid [2, 6, 10]
lst_processed: [10, 8]
- GetCandidate 1: 9 start 0.0
- GetCandidate 2: None None 9999
lst_todo [7]
lst_flip_oid [2, 6, 10]
lst_processed: [10, 8, 9]
- GetCandidate 1: 7 start 0.0
- GetCandidate 2: None None 9999
lst_todo []
lst_flip_oid [2, 6, 10]
lst_flip_oid : [2, 6, 10]
lst_candidates_todo : []
lst_multi_candidates: []
- Route: A seg id order: [1, 2, 3]
- Route: B seg id order: [4, 5, 6]
- Route: C seg id order: [7, 8, 9, 10]
At the end you will notice that oid's 2, 6 and 10 needs to be flipped (lst_flip_oid). Also the segment ID order for each route is provided.
