prepares post for regular upload

    :param str apikey: Apikey needed for Autentication on picflash.
    :param str/tuple/list picture: Path to picture as str or picture data. \
        If data a tuple or list with the file name as str \
        and data as byte object in that order.
    :param str resize: Aresolution in the folowing format: \
        '80x80'(optional)
    :param str|degree rotation: The picture will be rotated by this Value. \
        Allowed values are 00, 90, 180, 270.(optional)
    :param boolean noexif: set to True when exif data should be purged.\
        (optional)
    :param function callback: function witch will be called after every read. \
        Need to take one argument. you can use the len function to determine \
        the body length and call bytes_read().

def upload(apikey, picture, resize=None, rotation='00', noexif=False,
           callback=None):
    """
    prepares post for regular upload

    :param str apikey: Apikey needed for Autentication on picflash.
    :param str/tuple/list picture: Path to picture as str or picture data. \
        If data a tuple or list with the file name as str \
        and data as byte object in that order.
    :param str resize: Aresolution in the folowing format: \
        '80x80'(optional)
    :param str|degree rotation: The picture will be rotated by this Value. \
        Allowed values are 00, 90, 180, 270.(optional)
    :param boolean noexif: set to True when exif data should be purged.\
        (optional)
    :param function callback: function witch will be called after every read. \
        Need to take one argument. you can use the len function to determine \
        the body length and call bytes_read().
    """

    if isinstance(picture, str):
        with open(picture, 'rb') as file_obj:
            picture_name = picture
            data = file_obj.read()
    elif isinstance(picture, (tuple, list)):
        picture_name = picture[0]
        data = picture[1]
    else:
        raise TypeError("The second argument must be str or list/tuple. "
                        "Please refer to the documentation for details.")


    check_rotation(rotation)
    check_resize(resize)
    check_callback(callback)

    post_data = compose_post(apikey, resize, rotation, noexif)

    post_data['Datei[]'] = (punify_filename(basename(picture_name)), data)

    return do_upload(post_data, callback)