Python Intermediate — 046: Fold return ladders with pool discipline centred on `Exceptions: catching, chaining, guarding` [238559] — Learn

Lesson 046: Exceptions: catching, chaining, guarding

Focus

Compare against yesterday's mental model politely: Intermediate drills Exceptions: catching, chaining, guarding; spin token 440827 makes this page unlike its neighbours.

Key ideas

Angle Intermediate: micro cadence 6 mixes Exceptions: catching, chaining, guarding; spin 34827.
Ritual: Sketch control flow as ASCII before trusting output.
Own one invariant tied to Intermediate.

Example (`LESSON_UID = "intermediate-046"`)

# Intermediate drill L046 topic-4 micro-5 pattern-6
LESSON_UID = "intermediate-046"
spin_a, spin_b, spin_c = 652, 315, 829

start = 23 + 5 % 5
leap = 2
span = 10
bucket = []
for idx in range(start, start + span):
    bucket.append(idx * (spin_a % 37 + leap))
squares = tuple(x * x if x % 2 == (5 % 2) else -x for x in bucket[-4:])
print(bucket, squares)

from pathlib import Path
import tempfile

with tempfile.TemporaryDirectory() as scratch:
    target = Path(scratch) / "scratch-46.txt"
    snap = [59, 720, 390, 60]
    target.write_text("\n".join(str(x) for x in snap), encoding="utf-8")
    print("scratch_bytes", target.stat().st_size, "rolling", sum(snap) % (829 + 131))

Practice

Practice 12: Swap print order once; reconcile dependency thinking. Literal nudge 12.

Fingerprints

lesson_uid: intermediate-046
umbrella band: Exceptions: catching, chaining, guarding (6/10)
lesson_index: 1476