PIL isn’t an attribute of newImg1 but newImg1 is an instance of PIL.Image so it has a save method, thus the following should work.
newImg1.save("img1.png","PNG")
Note that just calling a file .png doesn’t make it one so you need to specify the file format as a second parameter.
try:
type(newImg1)
dir(newImg1)
and
help(newImg1.save)