python统计文本字符串里单词出现频率的方法

本文实例讲述了python统计文本字符串里单词出现频率的方法。分享给大家供大家参考。具体实现方法如下：

    # word frequency in a text
    # tested with Python24  vegaseat  25aug2005
    # Chinese wisdom ...
    str1 = """Man who run in front of car, get tired.
    Man who run behind car, get exhausted."""
    print "Original string:"
    print str1
    print
    # create a list of words separated at whitespaces
    wordList1 = str1.split(None)
    # strip any punctuation marks and build modified word list
    # start with an empty list
    wordList2 = []
    for word1 in wordList1:
      # last character of each word
      lastchar = word1[-1:]
      # use a list of punctuation marks
      if lastchar in [",", ".", "!", "?", ";"]:
        word2 = word1.rstrip(lastchar)
      else:
        word2 = word1
      # build a wordList of lower case modified words
      wordList2.append(word2.lower())
    print "Word list created from modified string:"
    print wordList2
    print
    # create a wordfrequency dictionary
    # start with an empty dictionary
    freqD2 = {}
    for word2 in wordList2:
      freqD2[word2] = freqD2.get(word2, 0) + 1
    # create a list of keys and sort the list
    # all words are lower case already
    keyList = freqD2.keys()
    keyList.sort()
    print "Frequency of each word in the word list (sorted):"
    for key2 in keyList:
     print "%-10s %d" % (key2, freqD2[key2])

希望本文所述对大家的Python程序设计有所帮助。