If you attempt to set the mode of an image directly, e.g.
im.mode = "RGBA", you will now receive an AttributeError. This is
not about removing existing functionality, but instead about raising an
explicit error to prevent later consequences. The convert method is the
correct way to change an image's mode.
TODO
TODO
Images now have :py:attr:`~PIL.Image.Image.has_transparency_data` to indicate whether the image has transparency data, whether in the form of an alpha channel, a palette with an alpha channel, or a "transparency" key in the :py:attr:`~PIL.Image.Image.info` dictionary.
Even if this attribute is true, the image might still appear solid, if all of the values shown within are opaque.
TODO
TODO