title: I don't know what happens in my ThreadPoolExecutor
body: <p>I am trying to create an automation to register hosts in Zabbix through its API asynchronously using concurrent.futures.ThreadPoolExecutor as you can see in this piece of code:</p>
  <pre><code>def zabbix_create_host(name, ip):
      session = get_session()
      token = get_token()
      print(&quot;     &quot;+name+&quot; &quot;+ip)
  
      headers = {'Content-type': 'application/json'}
      data = '{&quot;jsonrpc&quot;: &quot;2.0&quot;,&quot;method&quot;: &quot;host.create&quot;,&quot;params&quot;: {&quot;host&quot;: &quot;'+name+'&quot;,&quot;interfaces&quot;: [{&quot;type&quot;: 2,&quot;main&quot;: 1,&quot;useip&quot;: 1,&quot;ip&quot;: &quot;'+ip+'&quot;,&quot;dns&quot;: &quot;&quot;,&quot;port&quot;: &quot;10050&quot;}],&quot;groups&quot;: [{&quot;groupid&quot;: &quot;5&quot;}],&quot;templates&quot;: [],&quot;macros&quot;: [{&quot;macro&quot;: &quot;{$USER_ID}&quot;,&quot;value&quot;: &quot;123321&quot;}],&quot;inventory_mode&quot;: 0,&quot;inventory&quot;: {&quot;macaddress_a&quot;: &quot;01234&quot;,&quot;macaddress_b&quot;: &quot;56768&quot;}},&quot;auth&quot;: &quot;'+token+'&quot;,&quot;id&quot;: 1}'
      response = requests.post('http://127.0.0.1/api_jsonrpc.php', headers=headers, data=data)
      response = response.json()
  
  def zabbix_create_host_multiple(names, ips):
      with concurrent.futures.ThreadPoolExecutor(max_workers=12) as executor:
          df = pd.concat(executor,map(zabbix_create_host, names, ips))
      return df
  
  NAMES = ['PC1', 'PC2', 'PC3']
  IPS = ['1.1.1.1', '2.2.2.2', '3.3.3.3']
  
  zabbix_create_host_multiple(NAMES, IPS)
  </code></pre>
  <p>But when executing the code I get the following error:</p>
  <pre><code>  File &quot;main.py&quot;, line 159, in zabbix_create_hosts
      zabbix_create_host_multiple(names, ips)
    File &quot;main.py&quot;, line 173, in zabbix_create_host_multiple
      df = pd.concat(executor,map(zabbix_create_host, names, ips))
    File &quot;/home/sacarino/anaconda3/envs/aZabbix/lib/python3.8/site-packages/pandas/core/reshape/concat.py&quot;, line 274, in concat
      op = _Concatenator(
    File &quot;/home/sacarino/anaconda3/envs/aZabbix/lib/python3.8/site-packages/pandas/core/reshape/concat.py&quot;, line 328, in __init__
      objs = list(objs)
  TypeError: 'ThreadPoolExecutor' object is not iterable
  </code></pre>
  <p>Let's see if you can help me, it's the first time I've worked with this</p>