在正则表达式中获取带有一个连字符后跟4位数字的链接

Question

我的意图是提取类似http://www.realclearpolitics.com/epolls/2010/governor/ks/kansas_governor_brownback_vs_holland-1235.html链接

链接应以连字符，4位数字和html扩展名结尾

这是我的源代码

# coding=utf8
# the above tag defines encoding for this document and is for Python 2.x compatibility

import re

regex = r"http://www\.realclearpolitics\.com/epolls/\d{4}/governor/.+?\-\d{4}\.html"

test_str = "value=\"http://www.realclearpolitics.com/epolls/2010/house/wv/west_virginia_3rd_district_maynard_vs_rahall-1385.html\">West Virginia 3rd District</option> </select></p></div></div><div id=\"leftbox-latest\"><span class=\"sidebar-header\">2010 Governor Races</span><div id=\"poll_sidebar\"><p><strong><img src=\"http://assets.realclearpolitics.com/images/arrow_black.gif\" border=\"0\" alt=\"\" width=\"7\" height=\"10\" /><a href=\"http://www.realclearpolitics.com/epolls/2010/governor/2010_elections_governor_map.html\">RealClearPolitics Ratings</a></strong><br /> <strong><img src=\"http://assets.realclearpolitics.com/images/arrow_black.gif\" border=\"0\" alt=\"\" width=\"7\" height=\"10\" /><a href=\"http://www.realclearpolitics.com/epolls/2010/governor/2010_elections_governor_map_race_changes.html\">RCP Race-by-Race Changes</a></strong><br /> <strong><img src=\"http://assets.realclearpolitics.com/images/arrow_black.gif\" border=\"0\" alt=\"\" width=\"7\" height=\"10\" /><a href=\"http://www.realclearpolitics.com/epolls/2010/governor/2010_elections_governor_map_final_results.html\">Final Governors Map</a></strong><br /> <select class=\"search_by_race\" name=\"search_by_race\"> <option value=\"#\">Governor Races</option> <option value=\"http://www.realclearpolitics.com/epolls/2010/governor/al/alabama_governor_bentley_vs_sparks-1586.html\">Alabama Governor</option> <option value=\"http://www.realclearpolitics.com/epolls/2010/governor/ak/alaska_governor_parnell_vs_berkowitz-1510.html\">Alaska Governor</option> <option value=\"http://www.realclearpolitics.com/epolls/2010/governor/az/arizona_governor_brewer_vs_goddard-1409.html\">Arizona Governor</option> <option value=\"http://www.realclearpolitics.com/epolls/2010/governor/ar/arkansas_governor_keet_vs_beebe-1568.html\">Arkansas Governor</option> <option value=\"http://www.realclearpolitics.com/epolls/2010/governor/ca/california_governor_whitman_vs_brown-1113.html\">California Governor</option> <option value=\"http://www.realclearpolitics.com/epolls/2010/governor/co/colorado_governor_maes_vs_hickenlooper_vs_tancredo-1677.html\">Colorado Governor</option> <option "

matches = re.finditer(regex, test_str, re.MULTILINE)

for matchNum, match in enumerate(matches):
    matchNum = matchNum + 1

    print ("Match {matchNum} was found at {start}-{end}: {match}".format(matchNum = matchNum, start = match.start(), end = match.end(), match = match.group()))

    for groupNum in range(0, len(match.groups())):
        groupNum = groupNum + 1

        print ("Group {groupNum} found at {start}-{end}: {group}".format(groupNum = groupNum, start = match.start(groupNum), end = match.end(groupNum), group = match.group(groupNum)))

# Note: for Python 2.7 compatibility, use ur"" to prefix the regex and u"" to prefix the test string and substitution.

第一场比赛是错误的。 我不知道如何排除第一个，而包括其余的。 我相信正则表达式正在对连字符进行贪婪的搜索。 如果这是真的，该如何避免呢？

Answer 1

在您的正则表达式中，您使用. 可以匹配任何字符。 您需要使用[^"\\s]来限制该部分，以匹配除"或空格之外的任何字符。

我建议你用

regex = r'http://www\.realclearpolitics\.com/epolls/\d{4}/governor/[^\s"]+-\d{4}\.html'

参见Python演示

细节

• http://www\\.realclearpolitics\\.com/epolls/ -文字http://www.realclearpolitics.com/epolls/子字符串
• \\d{4} -4位数字
• /governor/ -文字子字符串
• [^\\s"]+ -除空格和"
• -连字符
• \\d{4} -4位数字
• \\.html - .html子字符串。