Regular Expressions 101

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'
(^[\/\\]*?)(\.git|node_modules|glue|doc|config|lib|tools)([\/\\]*$)
'
gm
1st Capturing Group
(^[\/\\]*?)
^ asserts position at start of a line
Match a single character present in the list below
[\/\\]
*? matches the previous token between zero and unlimited times, as few times as possible, expanding as needed (lazy)
\/ matches the character / with index 4710 (2F16 or 578) literally (case sensitive)
\\ matches the character \ with index 9210 (5C16 or 1348) literally (case sensitive)
2nd Capturing Group
(\.git|node_modules|glue|doc|config|lib|tools)
1st Alternative
\.git
\. matches the character . with index 4610 (2E16 or 568) literally (case sensitive)
git
matches the characters git literally (case sensitive)
2nd Alternative
node_modules
node_modules
matches the characters node_modules literally (case sensitive)
3rd Alternative
glue
glue
matches the characters glue literally (case sensitive)
4th Alternative
doc
doc
matches the characters doc literally (case sensitive)
5th Alternative
config
config
matches the characters config literally (case sensitive)
6th Alternative
lib
lib
matches the characters lib literally (case sensitive)
7th Alternative
tools
tools
matches the characters tools literally (case sensitive)
3rd Capturing Group
([\/\\]*$)
Match a single character 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 the character / with index 4710 (2F16 or 578) literally (case sensitive)
\\ matches the character \ with index 9210 (5C16 or 1348) literally (case sensitive)
$ 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