如何使用 Python 仅输出匹配字符串？答案

【问题标题】：How to output only the match string using Python?如何使用 Python 仅输出匹配字符串？
【发布时间】：2021-06-12 08:44:05
【问题描述】：

我想匹配一个字符串，然后打印匹配的字符串。

我需要从所有这些列表中匹配一个字符串mapping=C111。这是我尝试过的。我可以找到匹配的字符串，但我不能只打印匹配的字符串。

import re
AllString = ["123A","B456","AGHF\C111\B321","3FEW/D654"]
print(type(AllString))
for str in AllString:
    mapping = "C111"
    findid = [re.match(mapping, str)]
    for f in findid:
       if f is not None:
           print(f)

输出是这样的：

<re.Match object; span=(0, 4), match='C111'>

我的期望结果是"AGHF\C111\B321"整个字符串。

请大家帮忙。非常感谢

【问题讨论】：

标签： python string list output match

【解决方案1】：

import re
AllString = ["123A","B456","C111\B321","3FEW/D654"]
print(type(AllString))
for str in AllString:
    mapping = "C111"
    findid = [re.match(mapping, str)]
    for f in findid:
       if f is not None:
           print(f.string) # output: C111\B321 and It makes sense

或者：

import re
AllString = ["123A","B456","C111\B321","3FEW/D654"]
print(type(AllString))
for str in AllString:
    mapping = "C111"
    findid = [re.match(mapping, str)]
    for f in findid:
       if f is not None:
           print(mapping) # It meets your requirement but looks weird

新更新：

import re
AllString = ["123A","B456","AGHF\C111\B321","3FEW/D654"]
print(type(AllString))
for str in AllString:
    mapping = r".+C111.+" # method 'match' should be used with regex
    findid = [re.match(mapping, str)]
    for f in findid:
       if f is not None:
           print(f.string)

【讨论】：

嗨@Gcode。我尝试了您的第一个答案，它仅在我有 "C111\B321" 时才有效，但我的更新案例是“AGHF\C111\B321”，但它不起作用。如果中间的目标字符串像"AGHF\C111\B321"，则它不起作用。请你帮助我好吗。谢谢
我把它改成了findid = [re.search(mapping, str)] 它可以工作。谢谢你。您可以编辑您的答案

【解决方案2】：

代码的一个问题是re.match 必须在字符串的开头匹配。您可以改用re.search，但在这种情况下不需要正则表达式。使用in:

strings = ['123A','B456','AGHF\C111\B321','3FEW/D654']
for s in strings:
    if 'C111' in s:
        print(s)

AGHF\C111\B321

如果您需要匹配精确字母数字序列且其周围没有多余的字母/数字，则使用 re.search 和 \b（分词）：

import re

strings = ["123A","B456","C111\B321","3FEW/ABC111DEF/D654","ABC\C111/DEF"]

for s in strings:
    if re.search(r'\bC111\b',s):
        print(s)

C111\B321
ABC\C111/DEF

【讨论】：