Below is a for loop written in Python2.7 and it is throwing a syntax error while executed in Python3.3. I am new to this language and would like any help to understand what kind of for look is this? Thanks. :)

```
for link in (links.pop(0) for _ in xrange(len(links))):

```

I have changed xrange() to range() while executing. 'links' is a list of urls.