Разделить список на подсписки элементов между открывающими и закрывающими токенами

Question

У меня есть список строк (см. Ниже). Я хочу получить элементы в списке, ища два конкретных токена (начало и конец), а затем сохранить все строки, присутствующие между этими токенами.

Например, у меня есть список ниже, и я хочу получить все строки между любыми вхождениями строк 'RATED' и 'Like'. Эти подпоследовательности также могут встречаться несколько раз.

['RATED',
 '  Awesome food at a good price .',
 'Delivery was very quick even on New Year\xe2\x80\x99s Eve .',
 'Please try crispy corn and veg noodles From this place .',
 'Taste maintained .',
 'Like',
 '1',
 'Comment',
 '0',
 'Share',
 'Divyansh Agarwal',
 '1 Review',
 'Follow',
 '3 days ago',
 'RATED',
 '  I have tried schezwan noodles and the momos with kitkat shake',
 "And I would say just one word it's best for the best reasonable rates.... Gotta recommend it to everyone",
 'Like']

Я пробовал разные методы, например, regex, но ни один из них не решил проблему.

Answer 1

Опция без флагов:

new_list = []
group = [] # don’t need if the list starts with 'RATED'

for i in your_list:
    if i == 'RATED':
        group = []
    elif i == 'Like':
        new_list.append(group[:])
    else:
        group.append(i)

Answer 2

Вы можете использовать приведенный ниже код, который использует простой цикл for:

l = ['RATED','  Awesome food at a good price .', 'Delivery was very quick even on New Year’s Eve .', 'Please try crispy corn and veg noodles From this place .', 'Taste maintained .', 'Like', 
     '1', 'Comment', '0', 'Share', 'Divyansh Agarwal', '1 Review', 'Follow', '3 days ago',
     'RATED', '  I have tried schezwan noodles and the momos with kitkat shake', "And I would say just one word it's best for the best reasonable rates.... Gotta recommend it to everyone", 'Like'
]

st, ed, aa = None, None, []
for k, v in enumerate(l):
    if v == "RATED":
        st = k
    if v == "Like":
        ed = k
    if st != None and ed!= None:
        aa.extend(l[st+1: ed])
        st = None
        ed = None

print (aa)

# ['  Awesome food at a good price .', 'Delivery was very quick even on New Year’s Eve .', 'Please try crispy corn and veg noodles From this place .', 'Taste maintained .', '  I have tried schezwan noodles and the momos with kitkat shake', "And I would say just one word it's best for the best reasonable rates.... Gotta recommend it to everyone"]

Answer 3

Я бы посоветовал вам узнать о поиске и разрезании индекса по типам последовательностей:

• https://docs.python.org/3.7/library/stdtypes.html#common-sequence-operations

Пример:

def group_between(lst, start_token, end_token):
    while lst:
        try:
            # find opening token
            start_idx = lst.index(start_token) + 1
            # find closing token
            end_idx = lst.index(end_token, start_idx)
            # output sublist
            yield lst[start_idx:end_idx]
            # continue with the remaining items
            lst = lst[end_idx+1:]
        except ValueError:
            # begin or end not found, just skip the rest
            break

l = ['RATED','  Awesome food at a good price .', 'Delivery was very quick even on New Year’s Eve .', 'Please try crispy corn and veg noodles From this place .', 'Taste maintained .', 'Like', 
     '1', 'Comment', '0', 'Share', 'Divyansh Agarwal', '1 Review', 'Follow', '3 days ago',
     'RATED', '  I have tried schezwan noodles and the momos with kitkat shake', "And I would say just one word it's best for the best reasonable rates.... Gotta recommend it to everyone", 'Like'
]

for i in group_between(l, 'RATED', 'Like'):
    print(i)

Вывод:

['  Awesome food at a good price .', 'Delivery was very quick even on New Year’s Eve .', 'Please try crispy corn and veg noodles From this place .', 'Taste maintained .']
['  I have tried schezwan noodles and the momos with kitkat shake', "And I would say just one word it's best for the best reasonable rates.... Gotta recommend it to everyone"]

Answer 4

с помощью регулярных выражений вы можете сделать это следующим образом.

a= ['RATED','  Awesome food at a good price .', 
 'Delivery was very quick even on New Year’s Eve .', 
 'Please try crispy corn and veg noodles From this place .', 
 'Taste maintained .', 'Like', '1', 'Comment', '0', 
 'Share', 'Divyansh Agarwal', '1 Review', 'Follow', 
 '3 days ago', 'RATED', 
 '  I have tried schezwan noodles and the momos with kitkat shake', "And I would say just one word it's best for the best reasonable rates.... Gotta recommend it to everyone", 
 'Like']


import re
string = ' '.join(a)
b = re.compile(r'(?<=RATED).*?(?=Like)').findall(string)
print(b)

вывод

['   Awesome food at a good price . Delivery was very quick even on New Year’s Eve . Please try crispy corn and veg noodles From this place . Taste maintained . ',
 "   I have tried schezwan noodles and the momos with kitkat shake And I would say just one word it's best for the best reasonable rates.... Gotta recommend it to everyone "]

Answer 5

Вы можете использовать регулярное выражение Сначала вам нужно присоединиться к вашему списку с каким-либо разделителем, который не будет встречаться в тексте

delimiter = "#$#"
bigString = delimiter + delimiter.join(yourList) + delimiter

После этого вы можете использовать регулярное выражение

results = re.findall(r'#\$#RATED#\$#(.*?)#\$#Like#\$#', bigString)

Теперь вам просто нужно перебрать все результаты и разбить строку с разделителем

for s in results:
    print(s.split(delimiter))

Answer 6

def find_between(old_list, first_word, last_word):
    new_list = []
    flag = False
    for i in old_list:
        if i is last_word:
            break
        if i is first_word:
            flag = True
            continue
        if flag:
            new_list.append(i)
    return new_list

Answer 7

Вы можете попробовать, например,

rec = False
result = []
for s in lst:
    if s == 'Like':
        rec = False
    if rec:
        result.append(s)
    if s == 'RATED':
        rec = True

результат

#[' Awesome food at a good price .',
# 'Delivery was very quick even on New Year’s Eve .',
# 'Please try crispy corn and veg noodles From this place .',
# 'Taste maintained .',
# ' I have tried schezwan noodles and the momos with kitkat shake',
# "And I would say just one word it's best for the best reasonable rates.... Gotta recommend it to everyone"]