编写正则表达式解析含引号子串的查询并返回嵌套列表

Hey there! I know regex can feel overwhelming when you're starting out, but let's break this problem down into manageable parts. Your goal is to split a string like "green lizards" like to sit "in the sun" into a nested list where quoted substrings become inner lists of words, and regular words stay as strings—totally doable with a targeted regex and a bit of post-processing.

Step 1: The Regex Pattern #

First, we need a regex that can match two types of elements:

1. Substrings wrapped in single or double quotes
2. Regular words (sequences of non-whitespace characters)

Here's the pattern we'll use:

"([^"]+)"|'([^']+)'|(\S+)

Let's break down each part:

• "([^"]+)": Matches text wrapped in double quotes. The [^"]+ means "one or more characters that are NOT a double quote", and the parentheses capture the text inside the quotes (so we can extract it later).
• '([^']+)': Same as above, but for single quotes.
• (\S+): Matches any sequence of non-whitespace characters (your regular words), capturing them as a group.

The | acts like an OR—so the regex will try to match each part in order, stopping at the first match it finds.

Step 2: Processing the Matches #

Once we have all the matches, we need to convert them into your desired nested list structure. Let's use Python for this example (it's readable and widely used):

import re

def parse_quoted_text(input_string):
    # Define our regex pattern
    pattern = r'"([^"]+)"|\'([^\']+)\'|(\S+)'
    # Get all matches from the input string
    all_matches = re.findall(pattern, input_string)
    
    result = []
    for match_group in all_matches:
        # Check which group has content (only one will per match)
        if match_group[0]:
            # Double-quoted content: split into words and add as a list
            result.append(match_group[0].split())
        elif match_group[1]:
            # Single-quoted content: same as above
            result.append(match_group[1].split())
        else:
            # Regular word: add as a string
            result.append(match_group[2])
    
    return result

# Test it out!
test_input = '"green lizards" like to sit "in the sun"'
print(parse_quoted_text(test_input))
# Output: [['green', 'lizards'], 'like', 'to', 'sit', ['in', 'the', 'sun']]

Handling Edge Cases (Optional) #

If you need to handle escaped quotes (like "She said \"Hi!\""), we'll need to adjust the regex to ignore escaped quotes inside the quoted substring. Here's the updated pattern:

"((?:\\.|[^"])+)"|'((?:\\.|[^'])+)'|(\S+)

The (?:\\.|[^"])+ means:

• \\.: Match any escaped character (like \" or \')
• [^"]: Match any character that's not a quote
• The (?:...) is a non-capturing group—we use it to group these two options without creating an extra capture group.

Final Notes #

• The regex works because it prioritizes matching quoted substrings first (before regular words), so it won't split quoted content by spaces prematurely.
• The post-processing step is simple: we just check which capture group has content for each match, then convert quoted content into a list of words.

内容的提问来源于stack exchange，提问作者J. Taylor