In Python, is it better to use list comprehensions or for-each loops?

Which of the following is better to use and why?

Method 1:

for k, v in os.environ.items():
       print "%s=%s" % (k, v)

Method 2:

print "\n".join(["%s=%s" % (k, v) 
   for k,v in os.environ.items()])

I tend to lead towards the first as more understandable, but that might just be because I'm new to Python and list comprehensions are still somewhat foreign to me. Is the second way considered more Pythonic? I'm assuming there's no performance difference, but I may be wrong. What would be the advantages and disadvantages of these 2 techniques?

(Code taken from Dive into Python)

If the iteration is being done for its side effect ( as it is in your "print" example ), then a loop is clearer.

If the iteration is executed in order to build a composite value, then list comprehensions are usually more readable.

The particular code examples you have chosen do not demonstrate any advantage of the list comprehension, because it is being (mis-)used for the trivial task of printing. In this simple case I would choose the simple for loop.

In many other cases, you will want to supply an actual list to another function or method, and the list comprehension is the easiest and most readable way to do that.

An example which would clearly show the superiority of the list comp could be made by replacing the print example with one involving creating another actual list, by appending to one on each iteration of the for loop:

L = []
for x in range(10):
    L.append(x**2)

Gives the same L as:

L = [x**2 for x in range(10)]