Returning data to slack from errbot

I'm trying to get returned powershell output into slack via errbot. The bot is functioning correctly, running the code correctly and the output is being displayed in shell as expected. Can I send that returned data to slack via python code as is or do I need to return an object to return? Below I expect var x to give me the returned data, but it's obviously not.

@botcmd
def find_vm(self, args, SearchString):
    x = subprocess.call(["C:\\WINDOWS\\system32\\WindowsPowerShell\\v1.0\\powershell.exe", ". \"C:\\Program Files\\Toolbox\\PowerShell Modules\\vmware\\./vmware.psm1\";", "find-vm", SearchString])
    return x

subprocess.call does not return the output of the command, but returns returncode of the process. You need to use other functions like subprocess.check_output:

@botcmd
def find_vm(self, args, SearchString):
    try:
        output = subprocess.check_output([
            r"C:\WINDOWS\system32\WindowsPowerShell\v1.0\powershell.exe",
            r'. "C:\Program Files\Toolbox\PowerShell Modules\vmware\./vmware.psm1";',
            "find-vm",
            SearchString
        ])
    except subprocess.CalledProcessError:
        # Error handling
        return 'Command failed'
    return output

SIDE NOTE: Using raw string literals, you can express backslashes compactly:

>>> r"C:\WINDOWS\system32\WindowsPowerShell\v1.0\powershell.exe" == \
... "C:\\WINDOWS\\system32\\WindowsPowerShell\\v1.0\\powershell.exe"
True