Python 正则表达式的非捕获组详解

(?:pattern)

import re
text = "cat dog"
# 捕获组
match = re.search(r"(cat) (dog)", text)
print(match.groups())  # ('cat', 'dog')
print(match.group(1))  # cat
print(match.group(2))  # dog

import re
text = "cat dog"
# 非捕获组
match = re.search(r"(?:cat) (?:dog)", text)
print(match.groups())  # ()
print(match.group(0))  # cat dog

import re
text = "color colour"
# 捕获组
matches = re.findall(r"(col(or|our))", text)
print(matches)  # [('color', 'or'), ('colour', 'our')]
# 非捕获组
matches = re.findall(r"col(?:or|our)", text)
print(matches)  # ['color', 'colour']

import re
import time
text = "ab" * 100000
# 捕获组
start = time.time()
re.search(r"(ab)+", text)
print("捕获组耗时：", time.time() - start)
# 非捕获组
start = time.time()
re.search(r"(?:ab)+", text)
print("非捕获组耗时：", time.time() - start)

import re
text = "2024-02-19"
# 捕获组
match = re.search(r"(\d{4})-(\d{2})-(\d{2})", text)
print(match.groups())  # ('2024', '02', '19')
# 非捕获组
match = re.search(r"(?:\d{4})-(?:\d{2})-(?:\d{2})", text)
print(match.groups())  # ()