You can split the string into a list of words at a whitespace (space, spaces, tab, newline) ...
# convert a string to a list of words
str1 = 'You never find a missing item until you replace it'
print "Original string:"
# split the string into a list of words at a whitespace
wordList = str1.split(None)
print "String split into a list of words:"
# now print out each word in the list on a separate line
for word in wordList: