Python 3.4.1 (v3.4.1:c0e311e010fc, May 18 2014, 00:54:21) 
[GCC 4.2.1 (Apple Inc. build 5666) (dot 3)] on darwin
Type "copyright", "credits" or "license()" for more information.
>>> sentence = input("enter a sentence")
enter a sentencemy cat is white
>>> sentence
'my cat is white'
>>> sentence.split()
['my', 'cat', 'is', 'white']
>>> words = sentence.split()
>>> words
['my', 'cat', 'is', 'white']
>>> for word in words: print(word)

my
cat
is
white
>>> " ".join(words)
'my cat is white'
>>>