Equivalent of Bash Backticks in Python

The most flexible way is to use the subprocess module:

import subprocess

out = subprocess.run(["cat", "/tmp/baz"], capture_output=True)
print("program output:", out)

capture_output was introduced in Python 3.7, for older versions the special function check_output() can be used instead:

out = subprocess.check_output(["cat", "/tmp/baz"])

You can also manually construct a subprocess object if you need fine grained control:

proc = subprocess.Popen(["cat", "/tmp/baz"], stdout=subprocess.PIPE)
(out, err) = proc.communicate()

All these functions support keyword parameters to customize how exactly the subprocess is executed. You can for example use shell=True to execute the program through the shell, if you need things like file name expansions of *, but that comes with limitations.

output = os.popen('cat /tmp/baz').read()