There are a couple ways to go about doing this, but you should first export your excel table to an info table using the Excel to Table tool
Toolboxes\System Toolboxes\Conversion Tools.tbx\Excel\Excel To Table:
ArcGIS Help (10.2, 10.2.1, and 10.2.2)
if your excel table is setup the same as your example with a long list of coordinates for each entry in a single column then you could try a code similar to the following to parse the coordinate pairs:
polyline = arcpy.CreateFeatureclass_management("C:\Generate_Lines","Lines.shp","POLYLINE","","","",4326) # This generates an empty line shapefile with WGS 1984 spatial reference WKID: 4326
arcpy.AddField_management(polyline,"LineID","TEXT") # This adds a LineID field to the empty line layer
table = "C:\Generate_Lines\generatelines" # This references the table exported from excel
with arcpy.da.SearchCursor(table,["LINEID","LAT_LONG"]) as search:
for row in search:
array = arcpy.Array()
for i in range (len(row[1].split(","))/2):
array.add(arcpy.Point(row[1].split(",")[i*2+1],row[1].split(",")[i*2]))
with arcpy.da.InsertCursor(polyline,["SHAPE@","LineID"]) as insert:
insert.insertRow((arcpy.Polyline(array),row[0]))
The above search and insert cursor section loops through the 'table' which would reference the exported excel table that has the field names "LINEID" and "LAT_LONG". It will cycle through the lat / long entries and create an array that can be used to generate a polyline. This is all contingent on valid coordinate entries for polyline generation of course.
However, sometimes the above method may not produce desired results in which case you can generate a point layer first and then just use the standard Points to Line ArcGIS Help (10.2, 10.2.1, and 10.2.2) tool to generate lines based on LineID:
points = arcpy.CreateFeatureclass_management("C:\ArcGIS_LPS\EGIS_Help\Generate_Lines","Vertices.shp","POINT","","","",3857)
arcpy.AddField_management(points ,"LineID","TEXT")
table = "C:\Generate_Lines\generatelines"
with arcpy.da.SearchCursor(table,["LINEID","LAT_LONG"]) as search:
for row in search:
array = arcpy.Array()
for i in range (len(row[1].split(","))/2):
with arcpy.da.InsertCursor(points ,["SHAPE@","LineID"]) as insert:
insert.insertRow((arcpy.Point(row[1].split(",")[i*2+1],row[1].split(",")[i*2]),row[0]))
arcpy.PointsToLine_management(points,"C:\Generate_Lines\\generatelines.shp","LineID")
