Conditionally concatenate string values of a tuple in a list in python based on the elements

Question

Here is the list which includes tags to the word type

t = [('The','OTHER'),('name','OTHER'),('is','OTHER'),('Wall','ORGANIZATION'),('Mart','ORGANIZATION'),('and','OTHER'),('Thomas','ORGANIZATION'),('Cook','ORGANIZATION')]

The expectation is to conditionally check if the subsequent tuple is tagged as organization if so concatenate them with a space and continue with the same over the entire list.

Expected output:

Wall Mart, Thomas Cook

for x in t:
    if(x[1] == 'ORGANIZATION'):
         org_list = org_list + ' | ' + x[0]

I was just able to extract the names but not really getting a way where I could concatenate the words tagged as organization.

Refereed to other Question asked: [Link]Concatenate elements of a tuple in a list in python

Expected output: Wall Mart, Thomas Cook

`tenant_list = [item[0] for item in t if item[1] == 'ORGANIZATION']` will give you a list of the items you want — Nullman, May 27 '19 at 10:52
what should be the expected output for such input `[('Wall','ORGANIZATION'), ('and','OTHER'), ('Mart','ORGANIZATION'), ('Cook','ORGANIZATION')]` ? — RomanPerekhrest, May 27 '19 at 10:58
I want to concatenate the word in the subsequent tag as mentioned in the description what you have mentioned is just extracting the Words having organizations in them. — Amir Parkar, May 27 '19 at 10:59
@RomanPerekhrest Lol. Expected output should be: Wall, Mart Cook — Amir Parkar, May 27 '19 at 11:00
Will there always be an `OTHER` between two subsequent `ORGANIZATION`? — yatu, May 27 '19 at 11:01
@yatu Yes, there will be an OTHER between two subsequent ORGANIZATION. — Amir Parkar, May 27 '19 at 11:03

score 2 · Accepted Answer · edited May 27 '19 at 13:31

Given that there will always be an 'OTHER' between two subsequent 'ORGANIZATION', one approach is using itertools.groupby to group subsequent tuples by their second element, and str.join their first items if the grouping key is 'ORGANIZATION':

t = [('The','OTHER'),('name','OTHER'),('is','OTHER'),('Wall','ORGANIZATION'),
     ('Mart','ORGANIZATION'),('and','OTHER'),('Thomas','ORGANIZATION'),
     ('Cook','ORGANIZATION')]

from itertools import groupby
from operator import itemgetter as g

[' '.join(i[0] for i in [*v]) for k,v in groupby(t, key=g(1)) if k=='ORGANIZATION']
# ['Wall Mart', 'Thomas Cook']

If you prefer a for loop solution without any imports, you can do: -- This will work only for two subsequent tags:

f = False
out = []
for i in t:
    if i[1] == 'ORGANIZATION':
        if not f:
            out.append(i[0])
            f = True
        else:
            out[-1] += f' {i[0]}'
            f = False

print(out)
# ['Wall Mart', 'Thomas Cook']

Mykola Zotko · Answer 2 · 2019-05-27T12:00:18.880

You can use the following solution:

t = [('The','OTHER'),('name','OTHER'),('is','OTHER'),('Wall','ORGANIZATION'),('Mart','ORGANIZATION'),('and','OTHER'),('Thomas','ORGANIZATION'),('Cook','ORGANIZATION')]

result = [[]]
for i, j in t:
    if j == 'ORGANIZATION':
        result[-1].append(i)
    elif result[-1]:
        result.append([])       

result = [' '.join(i) for i in result if i]
# ['Wall Mart', 'Thomas Cook']

Conditionally concatenate string values of a tuple in a list in python based on the elements

2 Answers2