output=$(dmesg | grep hda)

  p1 = Popen(["dmesg"], stdout=PIPE)
  p2 = Popen(["grep", "hda"], stdin=p1.stdout, stdout=PIPE)
  p1.stdout.close()  # Allow p1 to receive a SIGPIPE if p2 exits.
  output = p2.communicate()[0]

You can write a simplifying function, but programs rarely do.

This is why I use the shell overall, but when I need to process something that's better expressed in python, I use pypyp.

  output = check_output(“dmesg | grep hda”, shell=True)

I actually find awk very readable. It's a far simpler language than Python really.

The exception is perhaps if you need to do something complex, like parse a csv.

This is true, but if you already know Python, then "awk + Python" has greater total complexity than "just Python". So the question is does awk add enough value to be worth the incremental cost of learning it in addition to Python? I think for many, the answer is "no".

It's like all of the bash scripts that we see that don't handle failures and traps or print a usage block.

     awk -F : '/\/home/ { print $1":"$3":"$4":"$6 } '

> I think the popularity of Python for scripting is pretty good evidence that PG was dead wrong on the importance of brevity in programming languages.

IMO Python has a fair number of brevity constructs, which was it's one of the selling points, besides keeping other things readable. If you look at the published code from the research community, many of it resembles Matlab or Mathematica's style.