Following your logic:
re.search(r'\[.*?\]\s*\w+:\s*(.+)', temp).group(1)
See proof
--------------------------------------------------------------------------------
\[ '['
--------------------------------------------------------------------------------
.*? any character except \n (0 or more times
(matching the least amount possible))
--------------------------------------------------------------------------------
\] ']'
--------------------------------------------------------------------------------
\s* whitespace (\n, \r, \t, \f, and " ") (0 or
more times (matching the most amount
possible))
--------------------------------------------------------------------------------
\w+ word characters (a-z, A-Z, 0-9, _) (1 or
more times (matching the most amount
possible))
--------------------------------------------------------------------------------
: ':'
--------------------------------------------------------------------------------
\s* whitespace (\n, \r, \t, \f, and " ") (0 or
more times (matching the most amount
possible))
--------------------------------------------------------------------------------
( group and capture to \1:
--------------------------------------------------------------------------------
.+ any character except \n (1 or more times
(matching the most amount possible))
--------------------------------------------------------------------------------
) end of \1

