atomic_write.py 文件源码

def atomic_write(filepath, binary=False, fsync=False):
    """ Writeable file object that atomically updates a file (using a temporary file). In some cases (namely Python < 3.3 on Windows), this could result in an existing file being temporarily unlinked.

    :param filepath: the file path to be opened
    :param binary: whether to open the file in a binary mode instead of textual
    :param fsync: whether to force write the file to disk
    """

    tmppath = filepath + '~'
    while os.path.isfile(tmppath):
        tmppath += '~'
    try:
        with open(tmppath, 'wb' if binary else 'w') as file:
            yield file
            if fsync:
                file.flush()
                os.fsync(file.fileno())
        replace(tmppath, filepath)
    finally:
        try:
            os.remove(tmppath)
        except (IOError, OSError):
            pass