tupledict.select() does not work as expected

Answered

Simon Hoof

• March 04, 2022 18:38

Consider the following MWE:

import gurobipy as gp

d = gp.tupledict([
    ((('AT','CH'),('BE','AT')), 1),
    ((('AT','CH'),('BE','DE')), 2),
    ((('AT','DE'),('BE','DE')), 3),
    ])   

print(d.select(('AT','CH'), '*'))

I was thinking that the selction yields \(\texttt{[1, 2]}\). It does not but returns an empty list.

Is it possible however, to get the desired result?

 

0

• 

  Eli Towle

  Gurobi Staff

  • March 04, 2022 21:04
  • Edited

  The keys of a tupledict should be a tuple of scalar values, not tuple values. From the tupledict documentation:

  Note that a \( \texttt{tupledict} \) key must be a tuple of scalar values (\(\texttt{int}\), \(\texttt{float}\), \(\texttt{string}\), ...). Thus, you can use \( \texttt{(1, 2.0, 'abc')}\) as a key, but you can't use \(\texttt{((1, 2.0), 'abc')}\).

  You get the desired result if you use four strings as the tupledict keys instead of two tuples:

  d = gp.tupledict([
      (('AT', 'CH', 'BE', 'AT'), 1),
      (('AT', 'CH', 'BE', 'DE'), 2),
      (('AT', 'DE', 'BE', 'DE'), 3),
      ])
  
  print(d.select('AT','CH', '*', '*'))

  0

Please sign in to leave a comment.