Originally posted by: alvarolorca

Hi,

I am trying to copy an instance of cplex, not by reference, in Python.

That is, I create an instance of cplex with "cpx1 = cplex.Cplex()", then I add lots of variables and constraints, but then I want to create a copy of it, that is, I do "cpx2 = cpx1", and want to add variables and constraints to cpx2 without changing cpx1, however, Python created cpx2 as a reference to cpx1 and I haven't found a way to avoid that. I want to do stuff with cpx2 and different stuff with cpx1, but create cpx2 at some point in the middle as an exact copy of cpx1.

(I know I could simply create cpx2 in the exact same way I created cpx1, but in my case that will take too long so I want to avoid that.)

Thank you,

Alvaro

You could do the following:

import cplex

cpx1 = cplex.Cplex()
# do stuff
cpx1.parameters.write_file('tmp.prm')
cpx1.write('tmp.sav')

cpx2 = cplex.Cplex()
cpx2.parameters.read_file('tmp.prm')
cpx2.read('tmp.sav')
# now cpx2 has a copy of cpx1's model

This isn't as ideal as being able to do something like this:

cpx2 = cpx1.copy() # this doesn't exist, it's just an example

I will add this to our user wish list for future consideration.

Regards,

Ryan

Originally posted by: alvarolorca

Thank you Ryan, that's actually fine enough for my purposes.

Best regards

Alvaro