Solution: Easy as Python

Answer: ORANGE PEEL

Solvers should start by solving the crossword clues. After looking at a few and considering the title and flavor text, they should realize that each answer can have a single letter removed to make a Python keyword.

Clue Answer Python Keyword Extra Letter
Peace agreement TRUCE TRUE C
Beethoven wrote a song for her ELISE ELSE I
Proficient or adept DEFT DEF T
A passage from a book EXCERPT EXCEPT R
This answer's length FOUR FOR U
Something that might come out of your nose SNOT NOT S
Former Japanese currency RIN IN R
Place to get a sandwich DELI DEL I
His first album was illmatic NAS AS N
Multiplied by height, it gives area WIDTH WITH D

Reading the extra letters in order gives the clue CITRUS RIND - along with the enumeration at the bottom, this clues ORANGE PEEL.

Notes

I realize it's a bit confusing to have the enumerations of both the final clue and the final answer be (6 4) - this hopefully helped more than it hurt, though if I had to do it again I might reconsider (6 4) -> (6 4) or similar. The underlying dataset is sadly fairly constrained beyond what is seen here.