copy.py 文件源码

def _copyFile(self, context, src, dest):
        dest = normLongPath(dest)
        src = normLongPath(src)
        with open(src, 'rb') as s:
            with openForWrite(dest, 'wb') as d:
                for m in self.mappers:
                    x = m.getHeader(context)
                    if x: 
                        self.__unusedMappers.discard(m)
                        d.write(x)

                for l in s:
                    for m in self.mappers:
                        prev = l
                        l = m.mapLine(context, l)
                        if prev != l:
                            self.__unusedMappers.discard(m)
                        if None == l:
                            break
                    if None != l:
                        d.write(l)

                for m in self.mappers:
                    x = m.getFooter(context)
                    if x: 
                        self.__unusedMappers.discard(m)
                        d.write(x)
        shutil.copymode(src, dest)
        assert os.path.exists(dest)