Finding words after keyword in python

Question

I want to find words that appear after a keyword (specified and searched by me) and print out the result. I know that i am suppose to use regex to do it, and i tried it out too, like this:

import re
s = "hi my name is ryan, and i am new to python and would like to learn more"
m = re.search("^name: (\w+)", s)
print m.groups()

The output is just:

"is"

But I want to get all the words and punctuations that comes after the word "name".

score 45 · Answer 1 · edited May 21 '19 at 19:55

45

Instead of using regexes you could just (for example) separate your string with str.partition(separator) like this:

mystring =  "hi my name is ryan, and i am new to python and would like to learn more"
keyword = 'name'
before_keyword, keyword, after_keyword = mystring.partition(keyword)
>>> before_keyword
'hi my '
>>> keyword
'name'
>>> after_keyword
' is ryan, and i am new to python and would like to learn more'

You have to deal with the needless whitespaces separately, though.

edited May 21 '19 at 19:55

Dan Russell

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answered Jul 09 '11 at 08:33

Aufwind

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What if there are multiple 'name' in the same sentence? Your solution wouldn't work then – Piyush Nov 07 '16 at 09:03
It should be `mystring.partition(keyword)` without the quotes around `keyword` – RaviTej310 Dec 19 '16 at 07:32
It will give spurious results if `keyword` appears multiple times in the string. – CKM Mar 21 '17 at 05:26
Thanks a lot for this :) – Anurag May 01 '20 at 17:41
Magnificent! Thank you! – Dmitriy Zub May 08 '21 at 08:24
What about if you wanted to print out the next word after 'name'? i.e. 'is' and not the entire second part of the sentence. Just the next word? – Hummer Nov 20 '21 at 08:54

score 20 · Answer 2 · answered Jul 09 '11 at 09:00

Your example will not work, but as I understand the idea:

regexp = re.compile("name(.*)$")
print regexp.search(s).group(1)
# prints " is ryan, and i am new to python and would like to learn more"

This will print all after "name" and till end of the line.

score 10 · Answer 3 · answered Jul 09 '11 at 11:21

10

An other alternative...

   import re
   m = re.search('(?<=name)(.*)', s)
   print m.groups()

answered Jul 09 '11 at 11:21

fransua

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score 4 · Answer 4 · edited Oct 17 '17 at 01:18

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import re
s = "hi my name is ryan, and i am new to python and would like to learn more"
m = re.search("^name: (\w+)", s)

print m.group(1)

edited Oct 17 '17 at 01:18

lebelinoz

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answered Oct 16 '17 at 20:53

krish

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score 3 · Answer 5 · answered Jul 09 '11 at 08:33

3

Instead of "^name: (\w+)" use:

"^name:(.*)"

answered Jul 09 '11 at 08:33

Petar Ivanov

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score 2 · Answer 6 · edited Mar 23 '17 at 07:44

2

This will work out for u : work name\s\w+\s(\w+)

>>> s = 'hi my name is ryan, and i am new to python and would like to learn more'
>>> m = re.search('name\s\w+\s(\w+)',s)
>>> m.group(0)
'name is ryan'
>>>> m.group(1)
'ryan'

edited Mar 23 '17 at 07:44

Jerry

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answered Mar 23 '17 at 06:30

Poovaraghan

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score 2 · Answer 7 · answered Jul 09 '11 at 08:36

2

What you have used regarding your output:

re.search("name (\w+)", s)

What you have to use (match all):

re.search("name (.*)", s)

answered Jul 09 '11 at 08:36

Tugrul Ates

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score 2 · Answer 8 · edited Mar 20 '15 at 18:44

2

You could simply do

s = "hi my name is ryan, and i am new to python and would like to learn more"
s.split('name')

This will split your string and return a list like this ['hi my', 'is ryan, and i am new to python and would like to learn more']

depending on what you want to do this may help or not.

edited Mar 20 '15 at 18:44

Parag Tyagi

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answered Jul 09 '11 at 08:48

Hassek

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philshem · Answer 9 · 2017-03-23T08:00:52.643

Without using regex, you can

strip punctuation (consider making everything single case, including search term)
split your text into individual words
find index of searched word
get word from array (index + 1 for word after, index - 1 for word before )

Code snippet:

import string
s = 'hi my name is ryan, and i am new to python and would like to learn more'
t = 'name'
i = s.translate(string.maketrans("",""), string.punctuation).split().index(t)
print s.split()[i+1]

>> is

For multiple occurences, you need to save multiple indices:

import string
s = 'hi my NAME is ryan, and i am new to NAME python and would like to learn more'
t = 'NAME'
il = [i for i, x in enumerate(s.translate(string.maketrans("",""), string.punctuation).split()) if x == t]
print [s.split()[x+1] for x in il]

>> ['is', 'python']

Finding words after keyword in python

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