如何获得循环范围中的值并在Python的循环外部使用它

Question

有人能帮助我思考解决此问题的方法吗？在下面的代码中，我列出并打开所有.log和.txt文件，以搜索特定的字符串。在最内部的for循环中，有一个if和else语句确定是否找到字符串。我想计算一个字符串在...中匹配的文件的数量，并通过某种方式将它传递给第三个（最后一个）for循环并显示...（例如，匹配的文件：4）。我仍然在学习python，所以我不知道所有可以加速这种努力的不同结构。我确信这是一个非常简单的问题，但除了死记硬背之外，我已经耗尽了我所知道的一切。谢谢！

... 

for afile in filelist: 
    (head, filename) = os.path.split(afile) 
    if afile.endswith(".log") or afile.endswith(".txt"): 
     f=ftp.open(afile, 'r') 
     for i, line in enumerate(f.readlines()): 
      result = regex.search(line) 
      if result: 
       ln = str(i) 
       pathname = os.path.join(afile) 
       template = "\nLine: {0}\nFile: {1}\nString Type: {2}\n\n" 
       output = template.format(ln, pathname, result.group()) 
       hold = output 
       print output 
       ftp.get(afile, 'c:\\Extracted\\' + filename) 
       temp.write(output) 
       break 
     else: 
      print "String Not Found in: " + os.path.join(afile) 
      temp.write("\nString Not Found: " + os.path.join(afile)) 

     f.close() 
for fnum in filelist: 
    print "\nFiles Searched: ", len(filelist) 
    print "Files Matched: ", count 
    num = len(filelist) 

    temp.write("\n\nFiles Searched: " + '%s\n' % (num)) 
    temp.write("Files Matched: ") # here is where I want to show the number of files matched 
    break 

Answer 1

如何：

count = 0 
for afile in filelist: 
    (head, filename) = os.path.split(afile) 
    if afile.endswith(".log") or afile.endswith(".txt"): 
     f=ftp.open(afile, 'r') 
     for i, line in enumerate(f.readlines()): 
      result = regex.search(line) 
      if result: 
       count += 1 
       ln = str(i) 
       pathname = os.path.join(afile) 
       template = "\nLine: {0}\nFile: {1}\nString Type: {2}\n\n" 
       output = template.format(ln, pathname, result.group()) 
       hold = output 
       print output 
       ftp.get(afile, 'c:\\Extracted\\' + filename) 
       temp.write(output) 
       break 
     else: 
      print "String Not Found in: " + os.path.join(afile) 
      temp.write("\nString Not Found: " + os.path.join(afile)) 

     f.close() 
for fnum in filelist: 
    print "\nFiles Searched: ", len(filelist) 
    print "Files Matched: ", count 
    num = len(filelist) 

    temp.write("\n\nFiles Searched: " + '%s\n' % (num)) 
    temp.write("Files Matched: "+str(count)) # here is where I want to show the number of files matched 
    break 

数从0开始，增量为每个文件有一个匹配。