Initializes the Xpress environment prior to creating or reading a problem.
Note that it is not necessary to call this function after importing the Xpress module and before creating or solving a problem, as Python will claim a license automatically. This function might be useful when the user wants to reserve a license and prevent that it is claimed by another user or program.

The following example shows how to call xpress.init and why it could be useful:

xp.init() # reserves the license before creating variables
x = xp.var()
y = xp.var()
p = xp.problem() # This would imply a call to xp.init()
p.addVariable(x, y)
p.addConstraint(x+y <= 1)
p.setObjective(x+2*y, sense=xp.maximize)
p.solve()

Note that the call to xpress.init is not necessary and should only be made when the user wants to claim a license that might be used by another program or user before the call to xpress.problem.

xpress.free