Finding words after keyword in python

问题

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".

回答1:

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.

回答2:

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.

回答3:

An other alternative...

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

回答4:

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

"^name:(.*)"

回答5:

What you have used regarding your output:

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

What you have to use (match all):

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

回答6:

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.

回答7:

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'

回答8:

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)

回答9:

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']

来源：https://stackoverflow.com/questions/6633678/finding-words-after-keyword-in-python

标签

python

regex

matching

keyword