《Python自然语言处理》第一章-练习17

 1 import nltk
 2 from nltk.book import *
 3 
 4 def solution():
 5     pun = [i for i,j in enumerate(text9) if j==‘.‘ or j==‘?‘ or j==‘!‘]
 6     sunset = [i for i,j in enumerate(text9) if j==‘sunset‘]
 7     ans = []
 8     flag = 0
 9     for i in range(len(sunset)):
10         j = flag
11         while j < len(pun):
12             if sunset[i] < pun[j] and pun[j-1] < sunset[i]:
13                 ans.append([pun[j-1]+1,pun[j]+1])
14                 flag = j + 1
15                 break
16             j += 1
17     print ans        
18     for i in range(len(ans)):
19         print ‘ ‘.join( text9[ ans[i][0] : ans[i][1]] )
20 
21 
22 def ref():
23     for var in [i for i,j in enumerate(text9) if j==‘sunset‘]:
24         ori_var=var
25         pun=[‘!‘,‘?‘,‘.‘]
26         start=0
27         stop=0
28         while start==0 or stop==0:
29             if text9[var] in pun and stop==0:
30                 stop=var+1
31                 var=ori_var
32             elif text9[var] not in pun and stop==0:
33                 var+=1
34             elif text9[var] not in pun and stop!=0 and start==0:
35                 var-=1
36             elif text9[var] in pun and stop!=0:
37                 start=var+1
38         print ‘start from %d to end in %d‘%(start,stop)
39         print ‘ ‘.join(text9[start:stop])
40 
41 
42 if __name__ == "__main__":
43     solution()
44     raw_input()