"Running Shell Scripts from Python"

There are about a million different ways to execute an external program from Python. Here's the right way:

import subprocess

subprocess.call('''zcat %s | tr '\02\03' '\r\n' | ssh %s "hadoop dfs -put - %s"''' %
     (local, DEST, remote), shell=True)

Where what you put inside the call statement is what gets executed in a shell. In this case I used pipes, escaping, etc, just to show a slightly complicated example; you could do something as simple as "ls" instead.

Lots more info in Doug Hellmann's PyMOTW article.