apis/examples_python/transport__neos_8py_source.html

import os

import ssl

import sys

import time

import xmlrpc.client

import certifi

from gams import GamsWorkspace


# NEOS XML Template (to be filled)

xml = r"""<document>

<category>:category:</category>

<solver>:solver:</solver>

<inputType>GAMS</inputType>

<email>:email:</email>

<priority>short</priority>

<model><![CDATA[:model:]]></model>

<wantgdx><![CDATA[yes]]></wantgdx>

<wantlog><![CDATA[yes]]></wantlog>

<wantlst><![CDATA[yes]]></wantlst>

</document>"""


if __name__ == "__main__":

    sys_dir = sys.argv[1] if len(sys.argv) > 1 else None

    ws = GamsWorkspace(system_directory=sys_dir)


    model = "trnsport"

    ws.gamslib(model)


    ssl_context = ssl.create_default_context()


    # explicitly point to 'certifi' *.pem file in case the OpenSSL default CA certificate path points to expired certificates

    if sys.platform == "win32":

        ssl_context.load_verify_locations(certifi.where())


    neos = xmlrpc.client.ServerProxy(

        "https://neos-server.org:3333", context=ssl_context

    )

    if "NeosServer is alive" not in neos.ping():

        raise Exception("Could not make connection to NEOS server")


    # can neither choose SoPlex nor CBC as LP solver on NEOS, so pretend its a MIP and use CBC

    xml = xml.replace(":category:", "MILP")

    xml = xml.replace(":solver:", "CBC")

    if "NEOS_EMAIL" in os.environ:

        xml = xml.replace(":email:", os.environ["NEOS_EMAIL"])

    else:

        raise Exception("Environment variable 'NEOS_EMAIL' not found")

    with open(os.path.join(ws.working_directory, model + ".gms"), "r") as f:

        xml = xml.replace(":model:", f.read())


    job_number, password = neos.submitJob(xml)

    print(f"Job number: {job_number}")

    print(f"Job password: {password}")


    if job_number == 0:

        raise Exception(f"NEOS server error: {password}")


    offset = 0

    echo = True

    status = ""

    while status != "Done":

        time.sleep(1)

        result, offset = neos.getIntermediateResults(job_number, password, offset)

        result = result.data.decode()

        if echo:

            if "Composing results." in result:  # this removes the lst output

                result = result.split("Composing results.", 1)[0]

                echo = False

            print(result, end="")

        status = neos.getJobStatus(job_number, password)


    result = neos.getFinalResults(job_number, password)

    with open(

        f"{job_number}-{os.path.splitext(os.path.basename(model + '.gms'))[0]}.lst", "w"

    ) as f:

        f.write(result.data.decode())

    result = neos.getOutputFile(job_number, password, "solver-output.zip")

    with open(f"{job_number}-solver-output.zip", "wb") as f:

        f.write(result.data)