python统计文本字符串里面单词出现的频率详解编程语言

python统计文本字符串里面单词出现的频率

# 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])