tee.py

import sys
import types

class Tee(object):
    """
    Contextmanager for writing simulaniously to multiple files.
    """
    def __init__(self, *args, **kwargs):
        """
        args -- file names or open file-like objects
        kwargs['mode'] -- mode for opening file names; see open.
        """
        self.files = args
        self.mode = kwargs.get('mode', 'w')
        self.handles = list()

    def _open(self, f):
        """
        Open argument if it is a file name.

        f -- file name or file like object.
        """
        if isinstance(f, types.StringTypes):
            return open(f, self.mode)
        else:
            return f

    def __enter__(self):
        return self.open_()

    def __exit__(self, type, value, traceback):
        self.close()

    def write(self, s):
        """
        Write `s' to all handles.
        See file.write.
        """
        for handle in self.handles:
            handle.write(s)

    def writelines(self, strings):
        """
        Write `strings' to all handles.
        See file.writelines.
        """
        for handle in self.handles:
            handle.writelines(strings)

    def open_(self):
        """Open all files."""
        self.handles = map(self._open, self.files)
        return self

    def close(self):
        """Close all files."""
        for handle in self.handles:
            if handle not in (sys.stderr, sys.stdout, sys.stdin):
                handle.close()

    @property
    def closed(self):
        """Return if any file handle is closed."""
        return any(handle.closed for handle in self.handles)

    def flush(self):
        """Flush all handles."""
        for handle in self.handles:
            handle.flush()