solvers.py 文件源码

def actualSolve(self, lp):
        """Solve a well formulated lp problem"""
        if not self.executable(self.path):
            raise PulpSolverError("PuLP: cannot execute "+self.path)
        if not self.keepFiles:
            pid = os.getpid()
            tmpLp = os.path.join(self.tmpDir, "%d-pulp.lp" % pid)
            tmpSol = os.path.join(self.tmpDir, "%d-pulp.sol" % pid)
        else:
            tmpLp = lp.name+"-pulp.lp"
            tmpSol = lp.name+"-pulp.sol"
        lp.writeLP(tmpLp, writeSOS = 0)
        proc = ["glpsol", "--cpxlp", tmpLp, "-o", tmpSol]
        if not self.mip: proc.append('--nomip')
        proc.extend(self.options)

        self.solution_time = clock()
        if not self.msg:
            proc[0] = self.path
            pipe = open(os.devnull, 'w')
            if operating_system == 'win':
                # Prevent flashing windows if used from a GUI application
                startupinfo = subprocess.STARTUPINFO()
                startupinfo.dwFlags |= subprocess.STARTF_USESHOWWINDOW
                rc = subprocess.call(proc, stdout = pipe, stderr = pipe,
                                     startupinfo = startupinfo)
            else:
                rc = subprocess.call(proc, stdout = pipe, stderr = pipe)
            if rc:
                raise PulpSolverError("PuLP: Error while trying to execute "+self.path)
        else:
            if os.name != 'nt':
                rc = os.spawnvp(os.P_WAIT, self.path, proc)
            else:
                rc = os.spawnv(os.P_WAIT, self.executable(self.path), proc)
            if rc == 127:
                raise PulpSolverError("PuLP: Error while trying to execute "+self.path)
        self.solution_time += clock()

        if not os.path.exists(tmpSol):
            raise PulpSolverError("PuLP: Error while executing "+self.path)
        lp.status, values = self.readsol(tmpSol)
        lp.assignVarsVals(values)
        if not self.keepFiles:
            try: os.remove(tmpLp)
            except: pass
            try: os.remove(tmpSol)
            except: pass
        return lp.status