Python: Cut off the last word of a sentence?

What's the best way to slice the last word from a block of text?

I can think of

1. Split it to a list (by spaces) and removing the last item, then reconcatenating the list.
2. Use a regular expression to replace the last word.

I'm currently taking approach #1, but I don't know how to concatenate the list...

conten开发者_JAVA技巧t = content[position-1:position+249] # Content
words = string.split(content, ' ')
words = words[len[words] -1] # Cut of the last word

Any code examples are much appreciated.

Actually you don't need to split all words. You can split your text by last space symbol into two parts using rsplit.

Example:

>>> text = 'Python: Cut off the last word of a sentence?'
>>> text.rsplit(' ', 1)[0]
'Python: Cut off the last word of a'

rsplit is a shorthand for "reverse split", and unlike regular split works from the end of a string. The second parameter is a maximum number of splits to make - e.g. value of 1 will give you two-element list as a result (since there was a single split made, which resulted in two pieces of the input string).

You should definitely split and then remove the last word because a regex will have both more complications and unnecessary overhead. You can use the more Pythonic code (assuming content is a string):

' '.join(content.split(' ')[:-1])

This splits content into words, takes all but the last word, and rejoins the words with spaces.

If you like compactness:

' '.join(content.split(' ')[:-1]) + ' ...'

If you want to keep your current method, use ' '.join(words) to concatenate the list.

You also might want to replace words = words[len[words -1] with words = words[:-1] to make use of list slicing.

OR

import re

print ' '.join(re.findall(r'\b\w+\b', text)[:-1])

Get last index of space and splice the string

>>> text = 'Python: Cut of the last word of a sentence?'
>>> text[:text.rfind(' ')]
'Python: Cut of the last word of a'

' '.join(words) will put the list back together.

        
def replace_ending(sentence, old, new):
    S1 = sentence
    O1 = old
    N1 = new
    # Check if the old string is at the end of the sentence 
    if O1 in S1:
        # Using i as the slicing index, combine the part
        # of the sentence up to the matched string at the 
        # end with the new string
        i = S1.rsplit(' ',1)[0] + str(" ") + N1     
        new_sentence = i
        return new_sentence

    # Return the original sentence if there is no match 
    return sentence
    
print(replace_ending("It's raining cats and cats", "cats", "dogs")) 
# Should display "It's raining cats and dogs"

Enother variant is to use an argument "args*"

For example:

def truncate_sentences(length, *sentences):
  for sentence in sentences:
    print(sentence[:length])

#call function

truncate_sentences(8, "What's going on here", "Looks like we've been cut off")

Would output:

"What's g"
"Looks li"

Let’s break this down:

1. We have two parameters that our function truncate_sentences() defines. The first is a length parameter that will specify how many characters we want to keep. The second is a parameter called sentences that is paired with the unpacking operator, signifying it will take a variable number of arguments.
2. On each iteration of the function, we are looping through the tuple created by the sentences argument (because it is paired with the unpacking operator) and perform a slice on the sentence based on the provided length argument. This forces every value in the sentences tuple to be cut down in length.

Try Below,

def replace_ending(sentence, old, new):
# Check if the old string is at the end of the sentence 
if sentence.endswith(old):
    # Using i as the slicing index, combine the part
    # of the sentence up to the matched string at the 
    # end with the new string
    i = sentence.rsplit(' ',1)[0] + str(" ")
    new_sentence = i + new
    return new_sentence

# Return the original sentence if there is no match 
return sentence