<p>您可以在函数<code>getwords</code><em>内的<code>getwords</code><em>在<code>try/except</code>块之后声明。如果<code>IOException</code>被引发,您只需<code>return</code>。这将在失败的<code>open</code>上返回<code>None</code>。将<code>words = []</code>移到<code>try/except</code>之前。在</p>
<p>这段代码现在应该可以工作了</strong>,没有异常。在</p>
<pre><code>def getwords():
#function to get words in the input file
words = []
try:
fp = open("sample.txt", "r")
except IOError:
return words
#read the file line by line
for line in fp:
#convert each line into words with space as delimiter
words=words+line.split()
return words
def wordcount(wordlist):
#function to count words in the file
#worddic is dictionary to store words frequency
worddic=dict()
for x in wordlist:
#convert word to lowercase to ignorecase
t=x.lower()
if(t not in worddic):
worddic[t]=0
worddic[t]=worddic[t]+1
max=-1
t=''
for x in worddic:
if(worddic[x]>max):
max=worddic[x]
t=x
return t
def letters(wordlist,lettercount):
#function to count letters in the file
for x in wordlist:
#For each word in the list
t=x.lower()
for y in t:
#for each letter in the word
if(not (y in lettercount)):
#if the letter is not in dictionary add it
#and set frequency to zero
lettercount[y]=0
#increment the frequency of letter in dictionary
lettercount[y] = lettercount[y]+1
def createoutput(lettercount,wordlist,mostword):
#creates an empty file 'statistics.txt'
try:
fout=open("statistics.txt",'w+')
except IOError:
print('Unable to create file')
fout.write('Number of words in the file are '+str(len(wordlist))+'\n')
fout.write('Most repeated word in the file is '+mostword+'\n')
for x in lettercount:
#write to the file 'statistics.txt'
fout.write(x+' appeared in the file for '+str(lettercount[x])+' times \n')
def main():
wordlist=getwords()
#lettercount is a dictionary with letters as keys
#and their frequency in the input file as data
lettercount=dict()
mostword=wordcount(wordlist)
letters(wordlist,lettercount)
createoutput(lettercount,wordlist,mostword)
main()
</code></pre>