python统计文本字符串里单词出现频率的方法

 # 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 =<p style="color:transparent">来源gao!daima.com搞$代!码网</p> 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])