Heroku MemCachier will not store cache - flask

Question

Quite new to this as I am trying to deploy MemCachier and I am quite new to code in general.
Followed this guide
https://devcenter.heroku.com/articles/flask-memcache
I have a function in a Flask app that will store a df in cache. I am working localy and didn't deploy the changes yet. The app is working fine and I can access the df in my app, but MemCachier GUI on Heroku does not display any data stored, so I am assuming its using cache.init_app(app, config={'CACHE_TYPE': 'simple'})
My code + function is:
#set memcache in Heroku
cache_servers = os.environ.get('MEMCACHIER_SERVERS')
if cache_servers == None:
cache.init_app(app, config={'CACHE_TYPE': 'simple'})
else:
cache_user = os.environ.get('MEMCACHIER_USERNAME') or ''
cache_pass = os.environ.get('MEMCACHIER_PASSWORD') or ''
cache.init_app(app,
config={'CACHE_TYPE': 'saslmemcached',
'CACHE_MEMCACHED_SERVERS': cache_servers.split(','),
'CACHE_MEMCACHED_USERNAME': cache_user,
'CACHE_MEMCACHED_PASSWORD': cache_pass,
'CACHE_OPTIONS': { 'behaviors': {
# Faster IO
'tcp_nodelay': True,
# Keep connection alive
'tcp_keepalive': True,
# Timeout for set/get requests
'connect_timeout': 2000, # ms
'send_timeout': 750 * 1000, # us
'receive_timeout': 750 * 1000, # us
'_poll_timeout': 2000, # ms
# Better failover
'ketama': True,
'remove_failed': 1,
'retry_timeout': 2,
'dead_timeout': 30}}})
def symbol_search():
flo = BytesIO()
directory = 'symboldirectory'
filenames = ('otherlisted.txt', 'nasdaqlisted.txt')
ftp = FTP('ftp.nasdaqtrader.com')
ftp.login()
ftp.cwd(directory)
#Create pandas dataframes from the nasdaqlisted and otherlisted files.
for item in filenames:
nasdaq_exchange_info=[]
ftp.retrbinary('RETR ' + item, flo.write)
flo.seek(0)
nasdaq_exchange_info.append(pd.read_fwf(flo))
ftp.quit()
# Create pandas dataframes from the nasdaqlisted and otherlisted files.
nasdaq_exchange_info=pd.concat(nasdaq_exchange_info, axis=1)
nasdaq_exchange_info[['symbol', 'name', 'Exchange', 'Symbol', 'etf', 'Lot_size', 'Test', 'NASDAQ_Symbol']]=nasdaq_exchange_info['ACT Symbol|Security Name|Exchange|CQS Symbol|ETF|Round Lot Size|Test Issue|NASDAQ Symbol'].str.split('|', expand=True)
nasdaq_exchange_info=nasdaq_exchange_info.drop(nasdaq_exchange_info.columns[[0]], axis=1).dropna()
nasdaq_exchange_info=nasdaq_exchange_info[(nasdaq_exchange_info['Test'] != 'Y') & (nasdaq_exchange_info['symbol'] != 'Y') & (~nasdaq_exchange_info.symbol.str.contains('symbol', 'file')) & (~nasdaq_exchange_info.name.str.contains('%', 'arrant'))]
nasdaq_exchange_info=nasdaq_exchange_info.drop(['Symbol', 'Exchange', 'Lot_size', 'Test', 'NASDAQ_Symbol', 'etf'], axis = 1)
nasdaq_exchange_info=nasdaq_exchange_info[['name', 'symbol']].values.tolist()
return cache.set("nasdaq_exchange_info", nasdaq_exchange_info)
symbol_search()
What I am missing here? and how can I upload the cache to MemCachier that it will be visible in the GUI?