Can a python script execute a function inside a bash script?

Question

I have a bash script provided by a 3rd party which defines a set of functions. Here's a template of what that looks like

$ cat test.sh

#!/bin/bash

define go() {
    echo "hello"
}

I can do the following from a bash shell to call go():

$ source test.sh
$ go
hello

Is there any way to access the same function from a python script? I tried the following, but it didn't work:

Python 2.6.6 (r266:84292, Sep 15 2010, 15:52:39) 
[GCC 4.4.5] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> import subprocess
>>> subprocess.call("source test.sh")
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
  File "/usr/lib/python2.6/subprocess.py", line 470, in call
    return Popen(*popenargs, **kwargs).wait()
  File "/usr/lib/python2.6/subprocess.py", line 623, in __init__
    errread, errwrite)
  File "/usr/lib/python2.6/subprocess.py", line 1141, in _execute_child
    raise child_exception
OSError: [Errno 2] No such file or directory
>>> 

Answer 1

Yes, indirectly. Given this foo.sh:

function go() { 
    echo "hi" 
}

Try this:

>>> subprocess.Popen(['bash', '-c', '. foo.sh; go'])

Output:

hi

Answer 2

Based on @samplebias solution but with some modification that worked for me,

So I wrapped it into function that loads bash script file, executes bash function and returns output

def run_bash_function(library_path, function_name, params):
    params = shlex.split('"source %s; %s %s"' % (library_path, function_name, params))
    cmdline = ['bash', '-c'] + params
    p = subprocess.Popen(cmdline,
                         stdout=subprocess.PIPE, stderr=subprocess.PIPE)
    stdout, stderr = p.communicate()
    if p.returncode != 0:
        raise RuntimeError("'%s' failed, error code: '%s', stdout: '%s', stderr: '%s'" % (
            ' '.join(cmdline), p.returncode, stdout.rstrip(), stderr.rstrip()))
    return stdout.strip()  # This is the stdout from the shell command