>>> a = 'jetpack ferret pizza lawyer'.split()
>>> a
['jetpack', 'ferret', 'pizza', 'lawyer']
>>> b = 'jetpack ferret pizza lawyer'
>>> b.split()
['jetpack', 'ferret', 'pizza', 'lawyer']
>>> b
'jetpack ferret pizza lawyer'
>>> c = """very
looooooooooooooooooooooong string with trailing random whitespace """
>>> c = c.split()
>>> c
['very', 'looooooooooooooooooooooong', 'string', 'with', 'trailing', 'random', 'whitespace']
>>> d = 'dog;_cat;_fish;_'.split(';_')
>>> d
['dog', 'cat', 'fish', '']
It is to note that most times you don't need to specify the separator (which can be made of mutiple characters).
If we simplify, giving no arguments to the split function gets you rid of all whitespace (i.e. spaces, tabs, newlines, returns), and this is a preferred behavior to work with input from a file, a shell etc, and also notably in a most common use of this idiom: hard coding a list of strings saving some annoying typing of commas and quotes.
Also be aware you're gonna get empty strings in your list if: