Originally posted by: AndyHam

The following doCplex Py code generates an error "list index out of range" at this line. 
    o_completedJOB = mdl.sum([mdl.presence_of(itvJobs[(j)]) for j in J])
I could not figure out why it is incorrect syntax.
Please help me. Thanks!
 

##################################

from docplex.cp.model import CpoModel
from collections import namedtuple

nbJob=4
J = range(1,nbJob)

mdl = CpoModel()

itvJobs = [mdl.interval_var(optional=True, name="itvJobs {}".format(j)) for j in J]

o_completedJOB = mdl.sum([mdl.presence_of(itvJobs[(j)]) for j in J])

mdl.add(mdl.maximize(o_completedJOB))

# Solve model
print("Solving model....")
msol = mdl.solve(TimeLimit=10)
print("Solution: ")
msol.print_solution()

##################################

Hi,

instead of

o_completedJOB = mdl.sum([mdl.presence_of(itvJobs[(j)]) for j in J])

you should write

o_completedJOB = mdl.sum([mdl.presence_of(itvJobs[j-1]) for j in J])

and then it will work fine.

regards