Clean code naming

Clean Code: Naming

Based on Robert C. Martin's Clean Code, Chapter 2: Meaningful Names.

When to Use This Skill

Trigger on:

• Naming or renaming variables, functions, classes, modules
• Code review flagging unclear identifiers
• Debates about naming conventions
• "What should I call this?" questions

Rules

1. Use Intention-Revealing Names

A name should tell you why it exists, what it does, and how it is used.

# Bad
d = 86400
elapsed_time_in_days = 86400

# Good
SECONDS_PER_DAY = 86400

2. Avoid Disinformation

Don't use names that mean something subtly different than what they represent.

# Bad — list implies specific type, but it could be any collection
account_list = get_accounts()

# Good
accounts = get_accounts()

3. Make Meaningful Distinctions

Don't use noise words that don't add meaning.

# Bad — these names don't distinguish concepts
def copy(a, b): ...
def copy1(source, destination): ...

# Good
def copy(source, destination): ...

4. Use Pronounceable Names

If you can't say it, you can't discuss it.

# Bad
genymdhms = datetime.now()

# Good
generation_timestamp = datetime.now()

5. Use Searchable Names

Single-letter names are hard to search. The length of a name should correspond to its scope.

# Bad — scope is large but name is cryptic
for j in range(len(users)):
    if users[j].age > 18:
        ...

# Good
for user in users:
    if user.age > 18:
        ...

6. Avoid Encodings

Don't prefix names with type information (Hungarian notation) or member prefixes.

# Bad
m_dsc = "description"   # member prefix
str_name = "Alice"       # type prefix

# Good
description = "description"
name = "Alice"

7. Class Names

Classes and objects should have noun or noun-phrase names. Avoid Manager, Processor, Data, Info.

8. Method Names

Methods should have verb or verb-phrase names. Accessors use get/set, predicates use is/has/can.

9. Don't Be Cute

Choose clarity over humor. whack() < delete(). holy_hand_grenade() < fast_delete().

10. Pick One Word Per Concept

Don't use fetch, retrieve, and get for the same concept. Pick one and stick with it.

11. Add Meaningful Context

Group related variables in a class or prefix consistently when context isn't available from scope alone.

Quick Checklist

• Does the name tell you what it does?
• Can you pronounce it?
• Can you search for it?
• Does it encode unnecessary type information?
• Is there a shorter, clearer alternative?
• Does it follow the project's naming conventions?

Source

Distilled from Clean Code by Robert C. Martin, Chapter 2: Meaningful Names.