mytheano_utils.py 文件源码

def editdist_np(source, target):
    if len(source) < len(target):
        return editdist_np(target, source)
    if len(target) == 0:
        return len(source)

    previous_row = np.arange(target.size + 1)
    for s in source:
        current_row = previous_row + 1
        current_row[1:] = np.minimum(current_row[1:], np.add(previous_row[:-1], target != s))
        current_row[1:] = np.minimum(current_row[1:], current_row[0:-1] + 1)
        previous_row = current_row

    return previous_row[-1]

# Pure python version
# from [https://en.wikibooks.org/wiki/Algorithm_Implementation/Strings/Levenshtein_distance#Python, the 6th version]