UPDATE: Here's a better example for Ruby syntax compared to LINQ.
I don't know much Ruby, but I'd suspect that blocks can simulate Linq far better than Python can. However, the Lambda-inspired syntax is a bit cluttered when compared to the SQL-inspired syntax.
Linq is a feature about 3 things:
1) Correctness via static typing checks
2) Interoperability of various data backends (Microsoft provides backends for XML, SQL, and .NET objects)
3) Clean and beautiful code
Neither Python nor Ruby can provide #1 (at compile time, anyway). SqlAlchemy and other projects attempt #2, but I don't have enough experience with them to comment on their success. And while Python as a whole (and I presume Ruby) has lots of #3, complex data querying is not the most beautiful experience.
The best way to learn Linq is with the 101 samples [1], but I might be bias because my friend wrote them [2].
[1] http://msdn.microsoft.com/en-us/vcsharp/aa336746.aspx
[2] http://www.microspotting.com/2007/12/anders-hejlsberg-intern