astropy/astropy — pull request #3132 by taldcroft (2014-11-24 14:51:30+00:00)
Title: Improve io.ascii.read guess when inputting file objects

In Python 3 (only) the following fails:
```
from astropy.io import ascii
t = ascii.read(open('astropy/io/ascii/tests/t/ipac.dat.bz2', 'rb'))
```
This is closely related to #3013 and issues raised in #3109. This PR puts in a fix in the `ui._guess()` which reads the entire file into memory if a file object is supplied. This fixes the Python 3 problem and should be more efficient in Python 2 because the file is not re-read during the guess process.