Python正则表达式：拆分冒号前含空格/非字母字符的字符串

Got it, let's solve this problem. The core challenge here is that we need to split the string at colon followed by space (: ) instead of just any colon—since the prefix (like Mark:))) or De'Angelo) can contain colons, apostrophes, spaces, and other special characters.

Approach #

Use re.findall() with a regex pattern that captures two groups for each entry:

1. The full prefix (including spaces, apostrophes, extra colons) up to the : separator.
2. The corresponding message content, which stops right before the next entry's [prefix]: or the end of the string.

Solution Code #

import re

input_str = "De'Angelo: hey everyone. Alexander the Great: wait. Alexander the Great: this is a weird script. Mark:))): Hello."

# Regex pattern to capture (prefix, message) pairs
pattern = r'(.+?): (.+?)(?=\s[^:]+?: |$)'
matches = re.findall(pattern, input_str)

# Flatten the list of tuples into a single list
result = [item for pair in matches for item in pair]

print(result)

Output #

["De'Angelo", 'hey everyone.', 'Alexander the Great', 'wait.', 'Alexander the Great', 'this is a weird script.', 'Mark:)))', 'Hello.']

Regex Breakdown #

Let's break down the pattern to understand how it works:

• (.+?): Non-greedy capture group for the prefix. It matches every character until it hits the : separator (we use lookahead to avoid consuming the separator). This preserves all special characters and spaces in the prefix.
• : : The literal separator we're targeting—this is what tells us where the prefix ends and the message begins.
• (.+?): Non-greedy capture group for the message. It matches characters until it sees the start of the next entry.
• (?=\s[^:]+?: |$): Positive lookahead that stops the message capture when it detects either:
  • A space followed by a new prefix ending with : (e.g., Alexander the Great:), or
  • The end of the string ($).

This approach ensures we don't accidentally split the prefix at internal colons and correctly extract all the required parts.

内容的提问来源于stack exchange，提问作者Agrosel