python - 正则表达式 - 在符号后查找数字

Question

我正在尝试使用下面的正则表达式来查找“|”之后的任何数字运算符来处理下面的几个示例字符串。问题在于默认的正则表达式，我似乎无法将 numerical_regex 与 Lookbehind 结合起来。

'xxx -> 31223.1 | xxx -> 1.1'.    to get 1.1

'0 | 1'     to get 1

numeric_regex = ''' 
                [-+]?                    # pos or neg
                (?: (?: \d* \. \d+ ) |   # float (ie .1 and 1.1)
                (?: \d+ \.? ) )          # int (with trailing periods ie 1.)
            '''

default_regex = f'''
                (? <= \|).               # after but not including |
                {numeric_regex}          # all digits
                + $                      # end of the string
            '''

感谢任何帮助!

Answer 1

以下是您的问题陈述的小程序

import re

regex = r"\|.*?[\-\+]?(\d+\.\d+|\d+\.?|\.\d+)"

test_str = ("xxx -> 31223.1 | xxx -> 1.1\n"
    "0|1\n"
    "0|abc 1.\n"
    "0|.1\n")

matches = re.finditer(regex, test_str)

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)))

你正在寻找的正则表达式是

regex = r"\|.*?[-+]?(\d+.\d+|\d+.?|.\d+)"

只测试了几个场景，希望对你有帮助。