Instead of precondition, I suggest setting up script tool input and output parameters like this
table = arcpy.GetParameterAsText(0)
arcpy.SetParameterAsText(1, True)
Setting script tool parameters—Help | ArcGIS Desktop
Then connect the combine table (data element in your model) to the script tool, and connect the script tool output to the Make Route Event Layer tool as a precondition. That should do it.
BTW, you need to format Python code for it to be readable here:
/blogs/dan_patterson/2016/08/14/script-formatting?sr=search&searchId=a6efc0d2-08b3-4930-b012-97b3576...
Another approach:
For a short bit if python snippet like this you can also use the Calculate Value tool and write a python function for your code, this can save you from the hassle of a separate script tool, passing parameters as text, and all that jazz.
proc(r"%combine%")
def proc(combine):
ridList = []
with arcpy.da.SearchCursor(table, ["RID"]) as cursor:
for row in cursor:
ridList.append(row[0])
del cursor
ridList = set(ridList)
for RID in ridList:
toMeasList = []
with arcpy.da.SearchCursor(table, ["RID", "END"], "RID = '{}'".format(RID)) as cursor:
for row in cursor:
toMeasList.append(row[1])
del cursor
toMeasList.sort()
with arcpy.da.UpdateCursor(table, ["END"], "RID = '{}'".format(RID)) as cursor:
for row in cursor:
row[0] = toMeasList[-1]
cursor.updateRow(row)
del cursor
toMeasList.sort()
with arcpy.da.UpdateCursor(table, ["OBJECTID"]) as cursor:
for row in cursor:
if row[0] == 2:
cursor.deleteRow()
del cursor
return True