ftp.py 文件源码

def openForReading(self, path):
        """
        Open C{path} for reading.

        @param path: The path, as a list of segments, to open.
        @type path: C{list} of C{unicode}
        @return: A L{Deferred} is returned that will fire with an object
            implementing L{IReadFile} if the file is successfully opened.  If
            C{path} is a directory, or if an exception is raised while trying
            to open the file, the L{Deferred} will fire with an error.
        """
        p = self._path(path)
        if p.isdir():
            # Normally, we would only check for EISDIR in open, but win32
            # returns EACCES in this case, so we check before
            return defer.fail(IsADirectoryError(path))
        try:
            f = p.open('r')
        except (IOError, OSError) as e:
            return errnoToFailure(e.errno, path)
        except:
            return defer.fail()
        else:
            return defer.succeed(_FileReader(f))