Find a single word between two parantences in regexpre python

Question

I don't know much about regular expressions. I need to extract a single word enclosed by left and right parentheses in a string.

For instance, in string

(ROOT (S (NP (NNP Washington) (NNP (CNN)) (NNP Donald) (NNP Trump)) (VP (VBD was) (VP (VBN asked) (PP ( by) (NP (NP (DT a) (NN member)) (PP (IN of) (NP (DT a) (NNP Fox) (NNP News) (NN town) (NN hall) (NN audience))))) (NP-TMP (DT this) (NN week)) (SBAR (WHNP (WP what)) (S (NP (PRP he)) (VP (MD would) (VP (VB do) (S (VP (TO to) (VP (VB reduce) (NP (JJ violent) (NN crime)) (PP (IN in) (NP (DT the) (NNS country's) (JJ inner) (NN cities.)))))))))))))) (NN debate,)) (ADJP (JJ due) (S (VP (TO to) (VP (VB be) (VP (VBN broadcast) (S (NP (JJ live)) (ADJP (RBS most) (RB everywhere.))))))))))))))))

I need to get (CNN) and ( by) substrings.

EDIT

    def fixeup_tree_string(T):
            change_index=[]
            Match = [(m.start(0), m.end(0),'Y') for m in re.finditer(r"\(\s*[\w|#|~|!|@|#|$|%|^|&|*|<|>|.|,|;|:|`|'''|_|-|+|/]+\s*\)", T)]
            if len(Match)==0:
            return T

            if Match[0][0]!=0:
            change_index.append((0,Match[0][0],'N'))
            for i in range(len(Match)-1):
                change_index.append(Match[i])
                change_index.append((Match[i][1],Match[i+1][0],'N'))
                change_index.append(Match[-1])
                if Match[len(Match)-1][1]< len(T):
                  change_index.append((Match[len(Match)-1][1],len(T),'N'))

            new_T = []
            for r in change_index:
            if r[2]=='N':
                for i in range(r[0],r[1]):
                    new_T.append(T[i])
            else:
                str = T[r[0]:r[1]].replace(' ','')
                str = str.split(')')[0].split('(')[-1]
                str = '(NN '+str +')'
                for x in str:
                    new_T.append(x)
            new_T = (''.join(new_T))
            return new_T

score 0 · Accepted Answer · edited Jun 20 '20 at 09:12

You could try:

y = re.findall(r"\(\s*[a-zA-Z]+\s*\)", x)

Where x is the input.

Note - You will have to import re by using the statement import re before the program, to use the regex functions

Explanation -

re.findall is a module that returns an array of the matches found by the regex. The arguments are as follows: regex, string

r"\(\s*[a-zA-Z]+\)" specifies that the regex is a raw string given by the r at the start.
\( means an opening bracket '('
\s* means that the opening bracket may be followed by xero-or-more spaces
[a-zA-Z]+matches the letters inside (one-or-more)
\s* indicates that the text may be followed by zero-or-more spaces, and then the \) indicates the closing ')'

Edit 1 -

To answer your second doubt in the comments, you could try this:

z = []

for i in y:
    str = "(NN " + i[1:]
    z.append(str)

print(z)

Find a single word between two parantences in regexpre python

1 Answers1

Explanation -