Get bash output with python

I'm trying to make a simple command that will let me run bash fully in Python, including output strings.

This function worked great on systems I use at my job:

import subprocess

def run(command):
    output = subprocess.check_output(command, shell=True)
    return output

However, now I'm using it at home and the PATH variable doesn't match the one in my Terminal.

So when I execute

run('ls')

I get this:

/bin/sh: ls: command not found

Which makes sense because, nonsensically, the PATH I get from running

print run('/usr/bin/env') 

is

PATH=/Library/Frameworks/Python.framework/Versions/Current/bin/

Now, I could remedy all this by using:

run('/bin/ls')

But that defeats the entire purpose of using this command, which is to faithfully emulate the bash shell.

How do I make run() use the system's PATH or create an equivalent function that just works?

(No platitudes about the dangers of using 'shell=True', please. This is all personal use with innocuous commands like ls and ps axw.)