Get ipython. Use it as your shell. This means move, copy, view, change, edit files from ipython. Day to day shell stuff anywhere has enough little problems that one ordinarily solves by piping, but are just as easily solvable by python. The real bonus is that your eye for syntax and simple solutions will develop quickly.
Need to find files? use os.walk,
Running grep? try to 'open' the file instead, try some regex while you are there. Those uses of the language will serve you in any type of python programming.
( Good news, PHP and python use the same underlying regex lib PCRE, so although there are some additions, it'll be familiar to you, )
The nice thing about having this in the language , which is not really the case in PHP or Perl, is that you can just mess around with functions, not full programs.
Why ipython and not the standard REPL or bpython? Easier to use as a shell out of the box. That's all.