Infor M3 ION API Gateway OAuth 2.0 Python Client Generator

import json
import time
import requests

IONAPI_PATH = 'C:/ionapi/M3_Integration.ionapi'
PROGRAM = 'CRS610MI'
TRANSACTION = 'GetBasicData'
CONO = '100'
DIVI = 'AAA'
MAXRECS = '100'
RETURNCOLS = 'CUNO,CUNM,STAT'
CA_BUNDLE = '[CA bundle for your internal TLS (blank uses system store)]' or True
INPUTS_TEXT = """CUNO=10001"""


class IonClient:
    def __init__(self, path):
        with open(path, encoding='utf-8') as f:
            self.cfg = json.load(f)
        self.token = None
        self.refresh = None
        self.expires = 0

    def _token_request(self, data):
        url = self.cfg['pu'] + self.cfg['ot']
        data['client_id'] = self.cfg['ci']
        data['client_secret'] = self.cfg['cs']
        r = requests.post(url, data=data, timeout=60, verify=CA_BUNDLE)
        r.raise_for_status()
        tok = r.json()
        self.token = tok['access_token']
        self.refresh = tok.get('refresh_token')
        self.expires = time.time() + int(tok.get('expires_in', 3600)) - 60

    def get_token(self):
        if self.token and time.time() < self.expires:
            return self.token
        if self.refresh:
            try:
                self._token_request({'grant_type': 'refresh_token', 'refresh_token': self.refresh})
                return self.token
            except requests.HTTPError:
                self.refresh = None
        self._token_request({
            'grant_type': 'password',
            'username': self.cfg['saak'],
            'password': self.cfg['sask'],
        })
        return self.token

    def execute(self, program, transaction, params):
        url = self.cfg['iu'].rstrip('/') + '/' + self.cfg['ti'] + '/M3/m3api-rest/v2/execute/' + program + '/' + transaction
        url += ';cono=' + CONO
        if DIVI:
            url += ';divi=' + DIVI
        query = dict(params)
        query['maxrecs'] = MAXRECS
        if RETURNCOLS:
            query['returncols'] = RETURNCOLS
        headers = {'Authorization': 'Bearer ' + self.get_token(), 'Accept': 'application/json'}
        r = requests.get(url, params=query, headers=headers, timeout=120, verify=CA_BUNDLE)
        r.raise_for_status()
        return r.json()


def parse_inputs(text):
    params = {}
    for line in text.splitlines():
        if '=' in line:
            k, v = line.split('=', 1)
            params[k.strip()] = v.strip()
    return params


if __name__ == '__main__':
    client = IonClient(IONAPI_PATH)
    data = client.execute(PROGRAM, TRANSACTION, parse_inputs(INPUTS_TEXT))
    if data.get('nrOfFailedTransactions'):
        for res in data.get('results', []):
            print('ERROR', res.get('errorMessage'), res.get('errorField'), res.get('errorCode'))
    else:
        for res in data.get('results', []):
            for rec in res.get('records', []):
                print(rec)