gistfile1.txt

def find_cmd_abspath(cmd):
    """ Returns the absolute path to a command.
        None is returned if no absolute path was found.
    """
    if exists(cmd) or exists(cmd + '.exe'):
        return os.path.abspath(cmd)
    if not 'PATH' in os.environ:
        raise Exception("Can't find command path for current platform ('%s')" % sys.platform)
    PATH = os.environ['PATH']
    for path in PATH.split(os.path.pathsep):
        for filename in os.listdir(path):
            barename = os.path.splitext(filename)[0]
            if filename == cmd or barename == cmd:
                return path + os.path.sep + filename
    return None