Re: Five Ways to Reverse a String of Words (C#, Perl 5, Perl6, Ruby, Haskell)

[stvn]

I didn't want Python to feel left out:

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

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 ;)

[webfiend]

TMTOWTDI even in Python, these days:

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

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.

[ambrus]

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'

[Anonymous Monk]

[word for word in words.split()] ?

No need for a list comprehensions here. How about this...

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

[paddy3118]

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