in reply to Five Ways to Reverse a String of Words (C#, Perl 5, Perl 6, Ruby, Haskell)

I didn't want Python to feel left out: 

def reverseWords (s):
    l = s.split(" ")
    l.reverse()
    return " ".join(filter(lambda x: x != '', l))

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It has been a long time since I hacked python, so I am sure there is a better way to do this, but then again, there might only be one way ;)

-stvn
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Re^2: Five Ways to Reverse a String of Words (C#, Perl 5, Perl6, Ruby, Haskell)
by webfiend (Vicar) on Dec 12, 2006 at 17:46 UTC

    TMTOWTDI even in Python, these days:

    def reverseWords(words):
    return ' '.join([word for word in words.split()][::-1])

    [download]

    I'd probably tweak it a bit in real-world code, though. Generators and list comprehensions make me go cross-eyed sometimes.

    Update: Adjusted the code to match the full goal.

[reply]
[d/l]

      You don't need [word for word in ...]. That's just the same as map { $_ } ... in perl, an identity op on lists (more or less). 

      >>> def reverseWords(words):
...     return ' '.join(words.split()[::-1])
... 
>>> reverseWords("  one   two three four    ")
'four three two one'

      [download]
[reply]
[d/l]
[select]
      [word for word in words.split()] ?

      [download]
      No need for a list comprehensions here. How about this... 
      def reverseWords(words):
    return ' '.join(words.split()[::-1])

      [download]
[reply]
[d/l]
[select]
        It is sometimes hard to not use ::-1 once learnt, but you can use reversed which makes it clearer: 
        >>> def reverseWords(word):
... 	return " ".join( reversed(word.split()) )
... 
>>> reverseWords("  one   two three four    ")
'four three two one'

        - Paddy
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