Regular Expressions 101

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"
\b-(\s+(?:and|to|or)(?:\s+\w+)*\s+\w+(-\w[\w-]*))
"
gm
\b assert position at a word boundary: (^\w|\w$|\W\w|\w\W)
- matches the character - with index 4510 (2D16 or 558) literally (case sensitive)
1st Capturing Group
(\s+(?:and|to|or)(?:\s+\w+)*\s+\w+(-\w[\w-]*))
\s
matches any whitespace character (equivalent to [\r\n\t\f\v  ])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
Non-capturing group
(?:and|to|or)
1st Alternative
and
and
matches the characters and literally (case sensitive)
2nd Alternative
to
to
matches the characters to literally (case sensitive)
3rd Alternative
or
or
matches the characters or literally (case sensitive)
Non-capturing group
(?:\s+\w+)*
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
\s
matches any whitespace character (equivalent to [\r\n\t\f\v  ])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
\w
matches any word character (equivalent to [a-zA-Z0-9_])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
\s
matches any whitespace character (equivalent to [\r\n\t\f\v  ])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
\w
matches any word character (equivalent to [a-zA-Z0-9_])
+ matches the previous token between one and unlimited times, as many times as possible, giving back as needed (greedy)
2nd Capturing Group
(-\w[\w-]*)
- matches the character - with index 4510 (2D16 or 558) literally (case sensitive)
\w matches any word character (equivalent to [a-zA-Z0-9_])
Match a single character present in the list below
[\w-]
* matches the previous token between zero and unlimited times, as many times as possible, giving back as needed (greedy)
\w matches any word character (equivalent to [a-zA-Z0-9_])
- matches the character - with index 4510 (2D16 or 558) 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

Substitution

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For a full regex reference for Python, please visit: https://docs.python.org/3/library/re.html