如何使用Python统计Java源代码中的注释行？

Question

这是我用来统计空行、源代码行、总行数和注释行的代码。我用来检查一行是否是注释行的方法是看里面有没有'//'，但我知道这样做不太对。因为'/*...*/'也可以形成一个注释块。那么，怎么才能统计注释块里的行数呢？

def FileLineCount(self,filename):
    (filepath,tempfilename) = os.path.split(filename);
    (shotname,extension) = os.path.splitext(tempfilename);
    if extension == '.java' : # file type 
        file = open(filename);
        self.sourceFileCount += 1;
        allLines = file.readlines();
        file.close();

        lineCount    = 0;
        commentCount = 0;
        blankCount   = 0;
        codeCount    = 0;
        for eachLine in allLines:
            if eachLine != " " :
                eachLine = eachLine.replace(" ",""); #remove space    #remove tabIndent
                if  eachLine.find('//') == 0 :  #LINECOMMENT 
                    commentCount += 1;
                else :
                    if eachLine == "":
                        blankCount += 1;
                    else :
                        codeCount += 1;
            lineCount = lineCount + 1;
        self.all += lineCount;
        self.allComment += commentCount;
        self.allBlank += blankCount;
        self.allSource += codeCount;
        print filename;
        print '           Total      :',lineCount ;
        print '           Comment    :',commentCount;
        print '           Blank      :',blankCount;
        print '           Source     :',codeCount;

Answer 1

你的代码有一些问题，比如你不能随便去掉所有的空格（因为你可能会把/{whitespace}/当成注释）。我不会给你具体的代码，但这应该能让你大致明白。

for each line of code  
1. Remove all white space from the beginning (left trimming).  
2. If mode is not multi-line and the line contains `//` increment counter.  
3. else if mode is not multi-line and the line contains `/*` go to multi-line mode.  
4. else if mode is multi-line  
           increment coutner
           if line contains `*/` exit multi-line mode

条件可以简化一下，不过我觉得你应该能让它正常工作。