[Python-Dev] Adding timeout to socket.py and httplib.py (original) (raw)

Alan Kennedy python-dev at alan.kennedy.name
Wed Mar 21 01:27:55 CET 2007

[Josiah]

Error-wise, I agree that it would be better to pass timeout explicitly with a keyword, but generally users will notice their mistake if they try to do createconnection(host, port) by ValueError("tuple expected as first argument, got str instead") Is it better than TypeError("createconnection takes 1 argument (2 given)") ?

Yes, it is better.

Currently, the socket.connect() method takes a tuple, and fails with the following exception if 2 separate parameters are passed

TypeError: connect() takes exactly one argument (2 given)

Which is fine because the function does take exactly one argument. But we're discussing a function with an optional timeout parameter, so that TypeError wouldn't be raised if I called create_connection("localhost", 80).

The patch as it currently is, if I am reading it right, would raise one of the following if a string was passed as the address argument, depending on the length of the string.

ValueError: need more than 1 value to unpack # len(address) == 1 ValueError: too many values to unpack # len(address) > 2

since it extracts the host and port like so

host, port = address

Which succeeds, somewhat surprisingly, if a string is passed that is 2 characters long. I was a little surprised to find that this didn't give rise to an error: host, port = "ab".

So with a two character hostname, the second letter would be unpacked as a port number. And the function would then fail with the following exception when it reaches the getaddrinfo ("a", "b", 0, SOCK_STREAM) call.

socket.gaierror: (10109, 'getaddrinfo failed')

I suggest updating the patch to

Regards,

Alan.

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