如何从python中的正则表达式匹配返回一个字符串？

参见英文答案 > Python extract pattern matches                                    8个
我正在使用python脚本在文本文件中运行行.
我想在文本文档中搜索img标记并将标记作为文本返回.

当我运行regex re.match(line)时,它返回一个_sre.SRE_MATCH对象.
如何让它返回一个字符串？

import sys
import string
import re

f = open("sample.txt", 'r' )
l = open('writetest.txt', 'w')

count = 1

for line in f:
    line = line.rstrip()
    imgtag  = re.match(r'<img.*?>',line)
    print("yo it's a {}".format(imgtag))

运行时打印：

yo it's a None
yo it's a None
yo it's a None
yo it's a <_sre.SRE_Match object at 0x7fd4ea90e578>
yo it's a None
yo it's a <_sre.SRE_Match object at 0x7fd4ea90e578>
yo it's a None
yo it's a <_sre.SRE_Match object at 0x7fd4ea90e578>
yo it's a <_sre.SRE_Match object at 0x7fd4ea90e5e0>
yo it's a None
yo it's a None

你应该使用re.MatchObject.group(0).喜欢

imtag = re.match(r'<img.*?>', line).group(0)

编辑：

你也可能会做更好的事情

imgtag  = re.match(r'<img.*?>',line)
if imtag:
    print("yo it's a {}".format(imgtag.group(0)))

消除所有Nones.