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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:

def get(filename, section, parameter):
    '''
    Get a value from an OpenStack configuration file.

    filename
        The full path to the configuration file

    section
        The section from which to search for the parameter

    parameter
        The parameter to return

    CLI Example:

    .. code-block:: bash

        salt-call openstack_config.get /etc/keystone/keystone.conf sql connection

    '''

    filename = _quote(filename)
    section = _quote(section)
    parameter = _quote(parameter)

    result = __salt__['cmd.run_all'](
            'openstack-config --get {0} {1} {2}'.format(
                filename, section, parameter
                ),
            python_shell=False,
            )

    if result['retcode'] == 0:
        return result['stdout']
    else:
        raise salt.exceptions.CommandExecutionError(result['stderr'])