ContinuumIO/blaze — pull request #304 by aterrel (2014-05-27 15:23:17+00:00)
Title: [WIP] Distinct

Adds a distinct operator to TableSymbols as needed for #303.

```
>>> from blaze.expr.table import *
>>> t = TableSymbol('{name: string, amount: int32}')
>>> expr = distinct(t['name'])

```