Switched from "+" for concatenation to "join" for performance.

Author: Kincaid Savoie

pssh/pssh_client.py

@@ -870,11 +870,6 @@ def copy_file_to_local(self, remote_file, local_file):
           Local directories in `local_file` that do not exist will be
           created as long as permissions allow.
 
-        .. note ::
-          Path separation is handled client side so it is possible to copy
-          to/from hosts with differing path separators, like from/to Linux
-          and Windows.
-
         .. note ::
           File names will be de-duplicated by appending the hostname to the
           filepath.
@@ -892,4 +887,4 @@ def _copy_file_to_local(self, host, remote_file, local_file):
                                                 password=self.password,
                                                 port=self.port, pkey=self.pkey,
                                                 forward_ssh_agent=self.forward_ssh_agent)
-        return self.host_clients[host].copy_file_to_local(remote_file, local_file + '_' + host)
+        return self.host_clients[host].copy_file_to_local(remote_file, '_'.join([local_file, host]))