Regular Expressions 101

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"
(?:UTF-8&q=+(.*)$|\?P=+(.*)$|\/search\/node\/+(.*)$)
"
gm
Non-capturing group
(?:UTF-8&q=+(.*)$|\?P=+(.*)$|\/search\/node\/+(.*)$)
1st Alternative
UTF-8&q=+(.*)$
UTF-8&q
matches the characters UTF-8&q literally (case sensitive)
=
matches the character = with index 6110 (3D16 or 758) literally (case sensitive)
1st Capturing Group
(.*)
.
matches any character (except for line terminators)
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
$ asserts position at the end of a line
2nd Alternative
\?P=+(.*)$
\? matches the character ? with index 6310 (3F16 or 778) literally (case sensitive)
P matches the character P with index 8010 (5016 or 1208) literally (case sensitive)
=
matches the character = with index 6110 (3D16 or 758) literally (case sensitive)
2nd Capturing Group
(.*)
.
matches any character (except for line terminators)
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
$ asserts position at the end of a line
3rd Alternative
\/search\/node\/+(.*)$
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
search
matches the characters search literally (case sensitive)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
node
matches the characters node literally (case sensitive)
\/
matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
3rd Capturing Group
(.*)
.
matches any character (except for line terminators)
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
$ asserts position at the end of a line
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