How to know if urllib.urlretrieve succeeds?

Question

urllib.urlretrieve returns silently even if the file doesn\'t exist on the remote http server, it just saves a html page to the named file. For example:

Answer 1

Results against another server/website - what comes back in "B" is a bit random, but one can test for certain values:

A: get_good.jpg
B: Date: Tue, 08 Mar 2016 00:44:19 GMT
Server: Apache
Last-Modified: Sat, 02 Jan 2016 09:17:21 GMT
ETag: "524cf9-18afe-528565aef9ef0"
Accept-Ranges: bytes
Content-Length: 101118
Connection: close
Content-Type: image/jpeg

A: get_bad.jpg
B: Date: Tue, 08 Mar 2016 00:44:20 GMT
Server: Apache
Content-Length: 1363
X-Frame-Options: deny
Connection: close
Content-Type: text/html

In the 'bad' case (non-existing image file) "B" retrieved a small chunk of (Googlebot?) HTML code and saved it as the target, hence Content-Length of 1363 bytes.