Writing and reading problem files

#!/bin/env python

#
# Create a few variables, then build a problem and save it to a file.
# Re-read that file into a new problem and solve it
#

from __future__ import print_function

import xpress as xp

m = xp.problem ()

c1 = xp.var (name = "C1", lb = -xp.infinity, ub = xp.infinity)
c2 = xp.var (name = "C2", lb = -xp.infinity, ub = 200)
c3 = xp.var (name = "C3", vartype = xp.partiallyinteger, threshold = 10)
c4 = xp.var (name = "C4", vartype = xp.semicontinuous, threshold = 3, ub = 6)
c5 = xp.var (name = "C5", vartype = xp.integer)

m.addVariable (c1, c2, c3, c4, c5)

m.setObjective (c1 + c2)

m.addConstraint (c1**2 + c2**2 <= 6,
                 2 * c1 + 3 * c2 + c3 == 2,
                 -c3**2 + c4**2 + c5**2 <= 0,
                 c4 == 0.316227766016838 * c1,
                 c5 == 0.316227766016838 * c2)

m.write ("example0", "lp")

m2 = xp.problem ()

m2.read ("example0.lp", "")

m2.solve ()

print ("objective value:", m2.getObjVal ())
print ("solution:", m2.getSolution ())