ftplib.FTP timeout has inconsistent behaviour

Question

I am trying to use ftplib.FTP() with timeout option as some timeout value for a particular hostname. But i am experiencing weird behaviour. To test it i have wr

Answer 1

ftplib.FTP invokes socket.create_connection(). According to the docs https://docs.python.org/2/library/socket.html#socket.create_connection

if host is a non-numeric hostname, it will try to resolve it for both AF_INET and AF_INET6, and then try to connect to all possible addresses in turn until a connection succeeds.

A quick check of google.com will show about a dozen (or more) depending on your region of the country. Your 2 second timeout is applied to each of the hosts.

If you want to limit total time to 2 seconds, do the lookup first and pass the numeric address to your ftplib.FTP call:

import socket, ftplib
host = socket.gethostbyname('google.com')
ftp = ftplib.FTP(host, timeout=2)