def load_src_wmap(path):
    """Loads a source side word map from the file system.
    
    Args:
        path (string): Path to the word map (Format: word id)
    
    Returns:
        dict. Source word map (key: word, value: id)
    """
    global src_wmap
    if not path:
        src_wmap = {}
        return src_wmap
    with open(path) as f:
        src_wmap = dict(map(lambda e: (e[0], int(e[-1])),
                        [line.strip().split() for line in f]))
    return src_wmap