Regular Expressions 101

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"
<(.+)>([^<>]*)</\1>
"
gm
< matches the character < with index 6010 (3C16 or 748) literally (case sensitive)
1st Capturing Group
(.+)
.
matches any character (except for line terminators)
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
> matches the character > with index 6210 (3E16 or 768) literally (case sensitive)
2nd Capturing Group
([^<>]*)
Match a single character not present in the list below
[^<>]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
<>
matches a single character in the list <> (case sensitive)
</
matches the characters </ literally (case sensitive)
\1 matches the same text as most recently matched by the 1st capturing group
> matches the character > with index 6210 (3E16 or 768) literally (case sensitive)
Global pattern flags
g modifier: global. All matches (don't return after first match)
m modifier: multi line. Causes ^ and $ to match the begin/end of each line (not only begin/end of string)
Your regular expression does not match the subject string.

Regular Expression
No Match

r"
"
gm

Test String