Implemented poll check as a global.

pychromecast/socket_client.py

@@ -56,6 +56,8 @@
 CONNECTION_STATUS_FAILED_RESOLVE = "FAILED_RESOLVE"
 # The socket connection was lost and needs to be retried
 CONNECTION_STATUS_LOST = "LOST"
+# Check for select poll method
+SELECT_HAS_POLL = hasattr(select,"poll")
 
 HB_PING_TIME = 10
 HB_PONG_TIME = 10
@@ -229,8 +231,6 @@ def __init__(
 
         self.receiver_controller.register_status_listener(self)
 
-        self.hasSelectPoll = hasattr(select,"poll")
-
     def initialize_connection(
         self,
     ):  # pylint:disable=too-many-statements, too-many-branches
@@ -568,7 +568,7 @@ def run_once(self, timeout=POLL_TIME_NON_BLOCKING):
         # poll the socket, as well as the socketpair to allow us to be interrupted
         rlist = [self.socket, self.socketpair[0]]
         try:
-            if self.hasSelectPoll == True:
+            if SELECT_HAS_POLL == True:
                 # Map file descriptors to socket objects because select.select does not support fd > 1024
                 # https://stackoverflow.com/questions/14250751/how-to-increase-filedescriptors-range-in-python-select
                 fd_to_socket = {rlist_item.fileno(): rlist_item for rlist_item in rlist}