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Python Craft & Sharp Edges

Mutable defaults, slots, descriptors, and the traps senior devs still step in.

Go beyond tutorials: mutable default arguments, __slots__, functools caches, dataclass footguns, pathlib patterns, and import machinery. Battle-tested wisdom you rarely find in blog posts.

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Practitioner6 lessons~4h
First lesson free

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Course content

Footguns

  • ○Mutable Default Arguments (The Classic)Free14 min

Performance & API

  • 🔒__slots__ — When and Why16 min

stdlib Secrets

  • 🔒functools.lru_cache — Hashability & Memory15 min
  • 🔒pathlib vs os.path — The Modern Way14 min

Modern Python

  • 🔒dataclass Field Defaults & Ordering16 min

Under the Hood

  • 🔒importlib — Loading Modules Programmatically18 min