为什么我的Python正则表达式不匹配查询字符串的一部分？
为什么我的Python正则表达式不匹配查询字符串的一部分？
提问于 2019-06-10 00:26:19
我使用的是Python 3.7。我想提取url在查询字符串的"q=...&“部分之间的部分。我有这个代码
href = span.a['href']
print("href:" + href)
matchObj = re.match( r'q=(.*?)\&', href, re.M|re.I)
if matchObj:
criteria = matchObj.group(1)但是尽管我的href是这样的
href:/search?hl=en-US&q=bet+i+won+t+get+one+share&tbm=isch&tbs=simg:CAQSkwEJyapBtj9kKiIahwELEKjU2AQaAAwLELCMpwgaYgpgCAMSKMILxAufFcsLnBWeFZsVnRWABMcPsCKgLaMtoi2hLZ0tqziiI6w4uSQaMG01mL5LQ62s4q5ZMf-Wetz68lCkHfrFOOKs2CELzQJlPjHIMzmlp2Ny-a5t7hZbiCAEDAsQjq7-CBoKCggIARIEXLNODAw&sa=X&ved=0ahUKEwjThcCx59ziAhWKHLkGHfWjDs4Q2A4ILCgB"matchObj“始终为NoneType，后面的行将不会被计算。我还需要做什么来修复我的正则表达式？
回答 1
Stack Overflow用户
发布于 2019-06-10 00:34:14
在这里，我们将应用一个具有左边界和右边界的简单表达式，例如：
&q=(.+?)&# coding=utf8
# the above tag defines encoding for this document and is for Python 2.x compatibility
import re
regex = r"&q=(.+?)&"
test_str = "href:/search?hl=en-US&q=bet+i+won+t+get+one+share&tbm=isch&tbs=simg:CAQSkwEJyapBtj9kKiIahwELEKjU2AQaAAwLELCMpwgaYgpgCAMSKMILxAufFcsLnBWeFZsVnRWABMcPsCKgLaMtoi2hLZ0tqziiI6w4uSQaMG01mL5LQ62s4q5ZMf-Wetz68lCkHfrFOOKs2CELzQJlPjHIMzmlp2Ny-a5t7hZbiCAEDAsQjq7-CBoKCggIARIEXLNODAw&sa=X&ved=0ahUKEwjThcCx59ziAhWKHLkGHfWjDs4Q2A4ILCgB
"
matches = re.finditer(regex, test_str, re.MULTILINE)
for matchNum, match in enumerate(matches, start=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.RegEx电路
jex.im可视化正则表达式：
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原文链接：
https://stackoverflow.com/questions/56516345
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