Regular Expressions 101

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"
^/pp/dc/dc[123]/h([1-9]{1,2}|100)$
"
gm
^ asserts position at start of a line
/pp/dc/dc
matches the characters /pp/dc/dc literally (case sensitive)
Match a single character present in the list below
[123]
123
matches a single character in the list 123 (case sensitive)
/h
matches the characters /h literally (case sensitive)
1st Capturing Group
([1-9]{1,2}|100)
1st Alternative
[1-9]{1,2}
Match a single character present in the list below
[1-9]
{1,2} matches the previous token between 1 and 2 times, as many times as possible, giving back as needed (greedy)
1-9 matches a single character in the range between 1 (index 49) and 9 (index 57) (case sensitive)
2nd Alternative
100
100
matches the characters 100 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