<p>What's the difference between <code>file</code> and <code>open</code> in Python?  When should I use which one?  (Say I'm in 2.5)</p>

You should always use
```
open()
```
.
As the
documentation
states:
When opening a file, it's preferable
  to use open() instead of invoking this
  constructor directly. file is more
  suited to type testing (for example,
  writing "isinstance(f, file)").
Also,
```
file()
```
has been removed
since Python 3.0.