Create a new item of the corresponding type and return its integer id. Each method is called as create_TYPE(coord..., **options): the leading positional arguments give the coordinates that define the item (as separate numbers, as a single sequence of numbers, or as coordinate pairs), and the keyword arguments set item-specific options. Coordinates and screen distances may be given as numbers (interpreted as pixels) or as strings with a unit suffix ('m', 'c', 'i' or 'p' for millimetres, centimetres, inches or printer’s points), but are always stored and returned in pixels.