import requests
import concurrent.futures

tracks_stor = []
with open('instances') as instances:
    instances = instances.read().split('\n')


def search_tracks_on_instance(instance, tag='', query=''):
    tracks = requests.get(f'https://{instance}/api/v1/tracks', params={'tag': tag, 'q': query}).json()
    return tracks
    #filter_tracks(tracks)

with concurrent.futures.ThreadPoolExecutor() as executor: # optimally defined number of threads
    res = [executor.submit(search_tracks_on_instance, instance, '', '') for instance in instances]
    concurrent.futures.wait(res)