Generator expressions v/s list comprehensions

[Martin DeMello]

Mahesh Padmanabhan <mahesh at privacy.net> wrote:
> 
> I am still not clear of the advantages of using generator expressions 
> (other than less memory consumption) instead of list comprehension for 
> any given class of problems. Can you cite concrete use cases where 
> generator expressions would be preferred over list comprehension?

Here's a simple example

linecount = sum(1 for line in file)
linecount = sum([1 for line in file])

The former requires an in-memory list equal to the size of the file.
Consigning "other than memory consumption" to a parenthetical remark
misses its importance.

martin