---input---
message.append(f" [line {lineno:2d}]")

---tokens---
'message'     Name
'.'           Operator
'append'      Name
'('           Punctuation
'f'           Literal.String.Affix
'"'           Literal.String.Double
' [line '     Literal.String.Double
'{'           Literal.String.Interpol
'lineno'      Name
':'           Literal.String.Interpol
'2d'          Literal.String.Double
'}'           Literal.String.Interpol
']'           Literal.String.Double
'"'           Literal.String.Double
')'           Punctuation
'\n'          Text.Whitespace