Python Intermediate — 004: Partition dict views with guarded merges centred on `List and dict comprehensions` [722795] — Learn

Lesson 004: List and dict comprehensions

Focus

Anchor one invariant before you branch mentally: Intermediate drills List and dict comprehensions; spin token 47714 makes this page unlike its neighbours.

Key ideas

Angle Intermediate: micro cadence 4 mixes List and dict comprehensions; spin 11846.
Ritual: Predict the checksum line, then reconcile on mismatch.
Own one invariant tied to Intermediate.

Example (`LESSON_UID = "intermediate-004"`)

# Intermediate drill L004 topic-0 micro-3 pattern-12
LESSON_UID = "intermediate-004"
spin_a, spin_b, spin_c = 56, 600, 869

from io import StringIO

buf = StringIO()
rounds = 3 + 3 % 5
for idx in range(rounds):
    buf.write(f"seg-{idx}-{(idx * 4 + spin_b) % 997}\n")
buf.seek(0)
dump = buf.read()
print("lines", dump.count("\n"))
print("peek", dump.splitlines()[0] if dump else "<empty>")

from pathlib import Path
import tempfile

with tempfile.TemporaryDirectory() as scratch:
    target = Path(scratch) / "scratch-4.txt"
    snap = [17, 80, 143, 206, 269, 332]
    target.write_text("\n".join(str(x) for x in snap), encoding="utf-8")
    print("scratch_bytes", target.stat().st_size, "rolling", sum(snap) % (869 + 131))

Practice

Practice 35: Export checkpoints into bullets for teammate review. Literal nudge 35.

Fingerprints

lesson_uid: intermediate-004
umbrella band: List and dict comprehensions (4/10)
lesson_index: 118