反转 Python 字符串中的单词（包括标点符号）

Question

I wrote a program to reverse the words in a given sentence here:

def rev_each_word_in(Sentence):

print(' '.join(Word[::-1] for Word in Sentence.split()))

As my input for Sentence I used "to be or not to be that is the question." This returns the following:

ot eb ro ton ot eb taht si eht .noitseuq

It's almost exactly what I want, but is there a way that the period could remain at the end of the sentence, so the return would be:

ot eb ro ton ot eb taht si eht noitseuq.

Thank you in advance!

Answer 1

It's possible to pass a function as the repl argument to re.sub() , so we can use that to match words and reverse them:

import re

def rev_each_word_in(sentence):
    return re.sub(r'\b\S*\b', lambda m: m.group(0)[::-1], sentence)

The pattern \\b\\S*\\b matches a word boundary, followed by an arbitrary number of non-whitespace characters, followed by a word boundary.

The function (a lambda, for brevity) takes group(0) (the complete text of the match) for each match, and reverses it the usual way using slicing.

Examples:

>>> rev_each_word_in('to be or not to be that is the question.')
'ot eb ro ton ot eb taht si eht noitseuq.'

>>> rev_each_word_in("whether 'tis nobler in the mind to suffer")
"rehtehw 'sit relbon ni eht dnim ot reffus"

>>> rev_each_word_in("aye, there's the rub")
"eya, s'ereht eht bur"

As you can see, this preserves the position of punctuation immediately before or after words, while maintaining it in the "correct" position inside each reversed word.

Answer 2

Here comes some ugliness that takes care of this in one line:

from string import punctuation as p
print(' '.join(w[::-1] if w[-1] not in p else w[:-1][::-1] + w[-1] for w in Sentence.split()))

Where we reverse fully if the last character in a word is not in the punctuation string and if it is we reverse the string up until the punctuation and then add the punctuation to it. prints out:

ot eb ro ton ot eb taht si eht noitseuq.

Slimming it down as much as I can because I'm ashamed of it:

# similar to  [::-1]
r = slice(None, None,-1)
# cut down chars!    
l = Sentence.split()
# reverse condition too and use shorter names
print(' '.join(w[:-1][r] + w[-1] if w[-1] in p else w[r] for w in l))

Answer 3

Your specifications are still unclear, but if you want only the letters to be reversed within a word, maybe you could try something like

def reverse_letters(word):
    lets = (c for c in reversed(word) if c.isalpha())
    return ''.join([c if not c.isalpha() else next(lets)
                    for c in word])

def reverse_sentence(sentence):
    words = sentence.split()
    return ' '.join([reverse_letters(word) for word in words])

which gives me

In [23]: reverse_sentence("to be or not to be, that is the question.")
Out[23]: 'ot eb ro ton ot eb, taht si eht noitseuq.'

In [24]: reverse_sentence("Don't try this at home!")
Out[24]: "tno'D yrt siht ta emoh!"

Answer 4

Change your method to this:

def rev_each_word_in(Sentence):
    if Sentence[-1] == '.':
        Sentence = Sentence[:-1]
        print(' '.join(Word[::-1] for Word in Sentence.split())+".")
    else:
        print(' '.join(Word[::-1] for Word in Sentence.split()))

Answer 5

import string

def reverse(sentence):
    punctuation = set(string.punctuation)
    words = []
    for word in sentence.split():
        words.append(word.rstrip(string.punctuation)[::-1])
        if word[-1] in punctuation:
           words[-1] = words[-1]+word[-1]
    return ' '.join(words)

Output:

In [152]: reverse("to be or not to be that is the question.")
Out[152]: 'ot eb ro ton ot eb taht si eht noitseuq.'

And this will work for any punctuation in your sentence:

In [153]: reverse("to be or not to be; that is the question.")
Out[153]: 'ot eb ro ton ot eb; taht si eht noitseuq.'

Answer 6

reverse a word in string input-'i.like.python.very.much.' output=.much.very.python.like.i