python简单应用：字数统计

每次写代码，LZ感觉还是得自己手敲一遍。。。一遍？一遍哪够？看着别人现成的代码觉得自己都能看的懂，等到自己上手解决自己任务的时候，才发现根本不是这么一回事。看了很多大神的博客，基本上都有一颗强大的内心，为啥？码了那么久的代码，结果一个bug就可能前功尽弃，从头再来，也是只能默默鼓励下自己：每天进步一点点！

"""Count words."""def count_words(s, n):    """Return the n most frequently occuring words in s."""    # TODO: Count the number of occurences of each word in s    import re    listOfTokens = re.split(r'\W*', s)    # print (listOfTokens)    ss = set(listOfTokens)    # print (ss)    bow = [0] * len(ss)    ll = list(ss)    for word in listOfTokens:        if word in ss:            bow[ll.index(word)] += 1    dd = {}    for i in range(len(ss)):        dd[ll[i]] = bow[i]    # sort_dd = sorted(dd.items(), key = lambda asd:asd[1], reverse = True)    sort_dd = sorted(dd.items(), key = lambda asd:(-asd[1], asd[0]))    top_ll = dict(sort_dd[0:n])    top_n = top_ll.keys()    # TODO: Return the top n most frequent words.    return top_ndef test_run():    """Test count_words() with some inputs."""    print (count_words("cat bat mat cat bat cat", 3))    print (count_words("betty bought a bit of butter but the butter was bitter", 3))if __name__ == '__main__':    test_run()test_run()

代码量不大，但是对于python入门的新手任务来说还是有挑战的O(∩_∩)O