What is the global default timeout
I suspect this is implementation-dependent. That said, for CPython:
From socket.create_connection,
If no timeout is supplied, the global default timeout setting returned by :func:
getdefaulttimeoutis used.
From socketmodule.c,
static PyObject *socket_getdefaulttimeout(PyObject *self){ if (defaulttimeout < 0.0) { Py_INCREF(Py_None); return Py_None; } else return PyFloat_FromDouble(defaulttimeout);}Earlier in the same file,
static double defaulttimeout = -1.0; /* Default timeout for new sockets */So it looks like Py_None, aka None, is the default timeout. In other words, urlopen never times out. At least not from the Python end. I guess a timeout can still occur if the networking functions supplied by the OS have timeouts themselves.
Edit: oops, I guess I didn't need to go source diving for the answer at all, since it's right there in the docs.
A value of
Noneindicates that new socket objects have no timeout. When the socket module is first imported, the default isNone.