Python循环结合正则未正确向数组追加内容问题排查

代码目标是从指定URL获取Linux内核RT补丁的版本号，遍历每个版本对应的sha256sums.asc页面，提取符合patch-.*?\.tar\.xz格式的文件名到数组patches_full_versions中。预期数组应包含2.6到6.9全版本的文件名，但实际仅保留了早期2.6版本的内容。已确认所有版本的sha256sums.asc文件都能成功获取，但数组未按预期填充完整，后续版本的文件名并未加入数组。

patches_versions = []
patches_full_versions = []

RT_PATCHES_BASE_URL = "https://cdn.kernel.org/pub/linux/kernel/projects/rt/"

cleaner = re.compile("<.*?>") # For removing HTML tags later.

# Create array of patches versions:
patches_page_content = requests.get(RT_PATCHES_BASE_URL)
patches_page_content.raise_for_status()
stripped_content = re.sub(cleaner, "", patches_page_content.text)
for line in stripped_content.splitlines():
    x = False
    x = re.findall(r"[0-9]", line)
    if not line == "":
        if x:
            patches_versions.append(line.split("/")[0])

patch_name_pattern = re.compile(r'patch-.*?\.tar\.xz')
for x in patches_versions:
    patch_version_page_content = requests.get(f"{RT_PATCHES_BASE_URL}{x}/sha256sums.asc")
    patch_version_page_content.raise_for_status()
    for match in re.findall(patch_name_pattern, patch_version_page_content.text):
        patches_full_versions.append(match)

1. 版本号提取逻辑错误 #

原代码提取版本号时，仅通过判断行内有数字就拆分取第一个元素，导致patches_versions数组混入了无效值（比如页面中带数字的非版本行），后续请求这些无效版本的URL时，即使返回200，文件内也没有符合模式的文件名，看起来像是循环“停止”了。

修复方案：用精准正则匹配版本目录格式（如2.6/、3.10/），直接提取正确的版本号：

# 替换原版本提取循环
version_pattern = re.compile(r'^(\d+\.\d+)/$')
for line in stripped_content.splitlines():
    line = line.strip()
    match = version_pattern.match(line)
    if match:
        patches_versions.append(match.group(1))

2. 文件名匹配正则的问题 #

原正则r'patch-.*?\.tar\.xz'用了非贪婪匹配，在部分sha256sums.asc文件中，文件名和哈希值在同一行时，可能提前终止匹配，导致无法正确捕获完整文件名。另外，findall在正则有分组时会返回分组内容而非完整匹配，这里改用finditer获取完整匹配字符串更可靠。

优化正则与匹配方式：

patch_name_pattern = re.compile(r'patch-\d+\.\d+(-rt\d+)?\.tar\.xz')
# 遍历匹配时改用finditer获取完整字符串
matches = [match.group() for match in patch_name_pattern.finditer(patch_version_page_content.text)]
patches_full_versions.extend(matches)

完整修复后的代码 #

import re
import requests

patches_versions = []
patches_full_versions = []

RT_PATCHES_BASE_URL = "https://cdn.kernel.org/pub/linux/kernel/projects/rt/"

# 匹配版本目录行（如2.6/、6.9/）
version_pattern = re.compile(r'^(\d+\.\d+)/$')
# 匹配RT补丁文件名格式
patch_name_pattern = re.compile(r'patch-\d+\.\d+(-rt\d+)?\.tar\.xz')

# 获取版本列表页面
patches_page_content = requests.get(RT_PATCHES_BASE_URL)
patches_page_content.raise_for_status()

# 清理HTML标签并提取有效版本号
stripped_content = re.sub(re.compile("<.*?>"), "", patches_page_content.text)
for line in stripped_content.splitlines():
    line = line.strip()
    match = version_pattern.match(line)
    if match:
        patches_versions.append(match.group(1))

# 遍历每个版本提取文件名
for version in patches_versions:
    url = f"{RT_PATCHES_BASE_URL}{version}/sha256sums.asc"
    patch_version_page_content = requests.get(url)
    patch_version_page_content.raise_for_status()
    # 提取所有符合格式的文件名
    matches = [match.group() for match in patch_name_pattern.finditer(patch_version_page_content.text)]
    patches_full_versions.extend(matches)

# 验证结果
print(f"处理的版本总数: {len(patches_versions)}")
print(f"收集的文件总数: {len(patches_full_versions)}")
print("前后各5个样本文件:", patches_full_versions[:5], patches_full_versions[-5:])

内容的提问来源于stack exchange，提问作者megalamehaxxor