Python: Idiomatic Efficiency Reference

Python: Idiomatic Efficiency Reference

When to Use

• Use this skill when the task matches this description: Language-specific super-code guidelines for python.

Table of Contents

1. Comprehensions & Generators
2. Unpacking & Destructuring
3. Built-ins & stdlib
4. Functions & Defaults
5. Classes & Dataclasses
6. Error Handling
7. Type Hints
8. Anti-patterns specific to Python

1. Comprehensions & Generators {#comprehensions}

# ❌ Imperative accumulation
result = []
for item in items:
    if item.active:
        result.append(item.name.upper())

# ✅
result = [item.name.upper() for item in items if item.active]

# ❌ Dict built in a loop
d = {}
for k, v in pairs:
    d[k] = v

# ✅
d = dict(pairs)
# or
d = {k: v for k, v in pairs}