正则表达式获取某些拆分词之间的所有字符

Question

My string contains AND , OR and NOT keywords, each of them is always upper case and pre- and suffixxed with a space.

This is my test-string:

X OR Y OR Z Z AND ZY AND ZZ OR A OR B AND C NOT E NOT F

I would like to get:

• all blocks connected with AND and separated by either OR , NOT or the beginning/end of the string. For my example i am looking for ZZ AND ZY AND ZZ as well as B AND C . This is what i came up with, which returns Z AND ZY AND ZZ instead of ZZ AND ZY AND ZZ because of the \w , but i can not up with any better idea:

import re

input_string = "X OR Y OR Z Z AND ZY AND ZZ OR A OR B AND C NOT E NOT F"
and_pairs = re.findall("\w AND .+?(?= OR | NOT )", input_string )

• also i would need all terms preceeded by a NOT , as well as all terms followed by an OR in separate lists.

I dont want to seem lazy, but regex is driving me crazy (unintended rhyme).

Answer 1

I think this should do the trick,

result:

>>> t_string = "X OR Y OR Z Z AND ZY AND ZZ OR A OR B AND C NOT E NOT F"
>>> [item.strip() for sublist in [x.split('NOT') for x in t_string.split('OR')] for item in sublist if 'AND' in item]
['Z Z AND ZY AND ZZ', 'B AND C']

Answer 2

Here's how to find the AND pairs:

import re

input_string = "X OR Y OR Z Z AND ZY AND ZZ OR A OR B AND C NOT E NOT F"
matchRegex = r"(.*?)(?:(?: OR | NOT )(\w+))+?"

regexdata = re.findall(matchRegex, input_string)
regexdata = list(sum(regexdata,())) # flatten matches
print(regexdata)

matches = [""]
for idx, data in enumerate(regexdata): # combine separated matches
        if idx % 2 == 0: matches[-1] += data
        else: matches.append(data)
print(matches)

matches = list(filter(lambda match: "AND" in match, matches)) # 'and' pairs only
print(matches)

Output:

['X', 'Y', '', 'Z', ' Z AND ZY AND ZZ', 'A', '', 'B', ' AND C', 'E', '', 'F']
['X', 'Y', 'Z Z AND ZY AND ZZ', 'A', 'B AND C', 'E', 'F']
['Z Z AND ZY AND ZZ', 'B AND C']

What this does is first it matches with the regex, then it combines the separated regex groups (index 1 and 2 should be combined, 3 and 4, and so on). Once that is complete, it filter out and outputs only the AND connected parts. If you don't need that last part you can remove it.

Answer 3

try with split

input_string = "X OR Y OR Z Z AND ZY AND ZZ OR A OR B AND C NOT E NOT F"
split_pairs = re.split("( OR | NOT )", input_string)
and_pairs = list(filter(lambda split_pairs: "AND" in split_pairs, split_pairs))
print(and_pairs)

result

['ZZ AND ZY AND ZZ', 'B AND C']