name of the subexpression
pointer to location where to store the start position, or NULL. out[allow-none]
pointer to location where to store the end position, or NULL. out[allow-none]
TRUE if the position was fetched, FALSE otherwise. If the position cannot be fetched, start_pos and end_pos are left unchanged.
Retrieves the position in bytes of the capturing parentheses named name. If name is a valid sub pattern name but it didn't match anything (e.g. sub pattern "X", matching "b" against "(?P<X>a)?b") then start_pos and end_pos are set to -1 and TRUE is returned. Since 2.14