Basic IG API client with instrument tree traversal methods

ig_client.py

import requests
import time

class IG:
    def __init__(self, username, password, api_key, base_url='https://api.ig.com/gateway/deal'):
        self.session_init(username, password, api_key, base_url, currency)

    def session_init(self, username, password, api_key, base_url):
        self.base_url = base_url 
        self.headers = {
                'Content-Type': 'application/json; charset=UTF-8',
                'Accept': 'application/json; charset=UTF-8',
                'VERSION': '2'}  
        self.headers['X-IG-API-KEY'] = api_key
        self.session = requests.post(f'{self.base_url}/session',
                          json={'identifier': username, 'password': password, 'encryptedPassword': False},
                          headers=self.headers)
        self.headers['CST'] = self.session.headers['CST']
        self.headers['X-SECURITY-TOKEN'] = self.session.headers['X-SECURITY-TOKEN']
        self.headers_v1 = dict(self.headers)
        self.headers_v1['VERSION'] = '1'

    def navigation(self, node_id):
        return requests.get(f'{self.base_url}/marketnavigation/{node_id}',
                            headers=self.headers_v1).json()
                            
    def traverse(self, node_id, markets=[], delay=2):
        level = self.navigation(node_id)
        print('.', end='', flush=True)
        time.sleep(delay)
        if 'nodes' in level and type(level['nodes']) == list:
            for node in level['nodes']:
                self.traverse(node['id'], markets)
        if 'markets' in level and type(level['markets']) == list:
            for market in level['markets']:
                markets.append(market)
        return markets
       
    def get_instruments(self, epics=[], filt='ALL'):
        return requests.get(f'{self.base_url}/markets',
                            params={'epics': ','.join(epics), 'filter': filt},
                            headers=self.headers).json()       

Did it work for you as expected?

Unfortunately not - I let it run without touching it for the past few days and nothing happened. And I'm not sure if there was any progress. For my purposes as a start I'm just trying to get the stocks within ASX200 and S&P500. Didn't know it would be this hard!