Dear all

Question

(?P<name>...
what is the letter P after ?

Answer 1

Can you specify language also?
It is generally a good practice to specify language in your question, at least in relevant tags.

Answer 2

Arsenic , this is python, regular expressions

Answer 3

(?P...) is used to denote a named capture group. All capture groups are numbered (and you can still refer to a named group using its number) but sometimes it is easier to give it a name.
(?P<name_a>...) can be referred to by using .group("name_a")

Answer 4

P is after?

Answer 5

The "P" here is Python identifier for a named capture group. 

Answer 6

After ? P is seeming as optional looking from python