Question

I am trying to write a socket server. The server itself doesn’t accomplish anything all that interesting. Right now my problem is that python is complaining about my arguments to select. Here is a snippet of code.

    read_client_sockets=[the_socket, clients]
    write_client_sockets=[clients, signals]
    error=[]
    #This is the loop that does most everything.
    while 1:
            #try to find someone who is ready for input
            ready_to_read, ready_to_write, in_error = select.select(all_client_sockets,    write_client_sockets, error)

Here is the complaint that I receive from my compiler. I have tried tweaking the arguments and end up getting the same result. Also I want this to run in blocking mode. As far as i know it is okay to not specify a timeout parameter; according to documentation I believe it is optional. Thank you for your time. I apologize for not having something more interesting to consider.

File "server.py", line 58, in main
    ready_to_read, ready_to_write, in_error = select.select(all_client_sockets, write_client_sockets, error)
TypeError: argument must be an int, or have a fileno() method.

Answer 1

You need to pass in three sequences of file descriptors as arguments to select, from the names you supply I think that [clients, signals] might be some other construct (is clients a list of file descriptors?). In this case you could use clients+signals as second argument to select.

In other words: Each argument must be a flat sequence, no nesting is allowed.