String slicing in python

Question

I want to slice word from the end.Suppose, I have some line with case sensitives(Upper/lower case)

Abc Defg Hijk Lmn
Xyz Lmn jkf gkjhg

I want to slice them as like below :

Abc Defg Hijk
Abc Defg
Abc

Then I need to take each sliced line in variables so that I can use them to search in some text file & return the whole text:

Suppose I have text :

 Akggf Abc Defg Hijk fgff jfkjgk djkfkgf     
 Akgff Abc fgff jfkjgk djkfkgf     
 Akggef Abc Defg  fgff jfkjgk djkfkgf
 gjshgs gskk Xyz Lmn jkf
 fgsgdf fkgksk Xyz Lmn

Any suggestions please.Thanks!

so those selections are the first 3, 2, and 1, words of the line? — Dan D.
– Dan D., Commented Jul 8, 2011 at 11:45
@Dan D.:Yes, it is. But I need to do this process globally & take each sliced line in varriables. — Big.Bang
– Big.Bang, Commented Jul 8, 2011 at 11:48

Roman Bodnarchuk · Accepted Answer · 2011-07-08 11:44:28Z

5

Use rsplit function:

>>> s = 'Abc Defg Hijk Lmn'
>>> s.rsplit(' ', 1)[0]
'Abc Defg Hijk'
>>> s = s.rsplit(' ', 1)[0]
>>> s.rsplit(' ', 1)[0]
'Abc Defg'

and so on...

Another variant:

>>> words = s.split()
>>> [' '.join(words[:i]) for i in range(len(words), 0, -1)]
['Abc Defg Hijk Lmn', 'Abc Defg Hijk', 'Abc Defg', 'Abc']

answered Jul 8, 2011 at 11:44

Roman Bodnarchuk

29.8k12 gold badges62 silver badges76 bronze badges

Sign up to request clarification or add additional context in comments.

1 Comment

Big.Bang Over a year ago

[' '.join(words[:i]) for i in range(len(words), 0, -1)] Like it! Many thanks.

Artsiom Rudzenka · Accepted Answer · 2011-07-08 12:35:37Z

1

You can also use the following code:

dataStr = 'Abc Defg Hijk Lmn'
for word in reversed(dataStr.split()):
    # do something with word

OR:

dataStr = 'Abc Defg Hijk Lmn'
removeLastWord = lambda line: ' '.join([word for word in line.split()[:-1]])
dataStr = removeLastWord(dataStr)
>>> 'Abc Defg Hijk'
dataStr = removeLastWord(dataStr)
>>> 'Abc Defg'
dataStr = removeLastWord(dataStr)
>>> 'Abc'

I have read your update and think that Roman's solution feats your needs. You can update your code the following way:

searchTxt = """Abc Defg Hijk Lmn
Xyz Lmn jkf gkjhg"""

data = """kggf **Abc Defg Hijk** fgff jfkjgk djkfkgf
 Akggf **Abc ** fgff jfkjgk djkfkgf
 Akggf **Abc Defg  fgff jfkjgk djkfkgf
 gjshgs gskk **Xyz Lmn jkf**
 fgsgdf fkgksk **Xyz Lmn**"""

searchWords = []
for line in (line for line in searchTxt.split('\n') if line.strip()):
    words = line.split()
    searchWords.extend([' '.join(words[:i]) for i in xrange(len(words), 0, -1)])

searchWords = sorted(searchWords, key=len, reverse=True)# to look first for the longest string match

res = set([line for sword in searchWords for line in data.split('\n') if sword in line])

# OR

res = []
for line in data.split('\n'):
    for sword in searchWords:
        if sword in line:
            res.append(line)
            break

And if you need to get a full text:

resultText = '\n'.join(res)

edited Jul 8, 2011 at 12:35

answered Jul 8, 2011 at 11:46

Artsiom Rudzenka

29.3k5 gold badges36 silver badges53 bronze badges

8 Comments

Big.Bang Over a year ago

@ Artsiom Rudzenka : Could you please a bit elaborate.I mean how to get the desired sliced line for many dataStr.Thanks!

Artsiom Rudzenka Over a year ago

Give me an example so i will be able to help you.

Big.Bang Over a year ago

@ Artsiom Rudzenka : I have updated the question.Could you please have a look!

Big.Bang Over a year ago

Could you please have a look over this part searchWords.extend([' '.join(words[:i]) for i in xrange(len(words), 0, -1)])

Artsiom Rudzenka Over a year ago

What is wrong with it? I have copied all code and rerun it - all is ok

|

Fredrik Pihl · Accepted Answer · 2011-07-08 11:47:34Z

0

To create a list from string:

a="Abc Defg Hijk Lmn".split()

look at it:

['Abc', 'Defg', 'Hijk', 'Lmn']

slice it, to remove last entry:

a[:-1]

This gives:

['Abc', 'Defg', 'Hijk']

To join it into a string again:

" ".join(a[:-1])

gives:

'Abc Defg Hijk'

Now, repeat that in a loop...

answered Jul 8, 2011 at 11:47

Fredrik Pihl

45.9k7 gold badges89 silver badges133 bronze badges

1 Comment

phant0m Over a year ago

Note that s != " ".join(s.split()) while s == " ".join(s.split(" ")) when s = "Two spaces"

Collectives™ on Stack Overflow

String slicing in python

3 Answers 3

1 Comment

8 Comments

1 Comment

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

3 Answers 3

1 Comment

8 Comments

1 Comment

Your Answer

Sign up or log in

Post as a guest

Related