Programming Style (in Python)

Basics

• Readability is important

• E.g.,

  My name is Ethan. I am 36 years old.

  MYnameIS ETHAN………………. I_AM_36 years OLD

• Using the same style as others is important (PEP 8)
• import this

Whitespace

• Indentation what the brain reconizes, use it regardless of language (and braces)
• 4 space indents
• Spaces after commas and around operators (almost always)

Naming

• joined_lower for functions
• StudlyCaps for classes

Long lines

• Lines < 80 characters long
• Use implied line continuation

Flow

• No compound statements

Docstrings and Comments

• Docstrings = How to use code (PEP 257
• Comments = Why & how code works

General approaches

Style also includes the general approaches for addressing regularly encountered problems. E.g.:

• Multi-value assignment
• List comprehensions
  • e.g., [a ** 2 for a in range(10)]
  • e.g., [a * b for a in range(1, 5) for b in range(1, 5) if a == b]
  • e.g., [a * b for a in range(1, 5) for b in range(a, 5)]
  • and Generator expressions - ``sum(a ** 2 for a in range(100))
• get() method for dictionaries
• if x: not if x == True: or if len(x) > 0:
• enumerate()
• EAFP (easier to ask forgiveness) no LBYL
  • assume that types are right and fail gracefully if not instead of checking types first