Operators

Python · Reference cheat sheet

📋 Overview

Python operators cover arithmetic, comparison, boolean logic, bitwise ops, membership, identity, and assignment variants. Precedence matters; use parentheses for clarity. Many operators map to magic methods.

🔧 Core concepts

/ always float division; // floor division. and/or return operands, not strict bools.

💡 Examples

Arithmetic and div:

print(7 / 2)    # 3.5
print(7 // 2)   # 3
print(7 % 2)    # 1
print(2 ** 10)  # 1024
print(-7 // 2)  # -4 (floors toward -inf)

Boolean and chaining:

x = 5
print(1 < x < 10)          # True — chained comparisons
print("" or "default")     # "default"
print("hi" and "there")    # "there"

Identity vs equality:

a = [1, 2]
b = [1, 2]
print(a == b)   # True — equal values
print(a is b)   # False — different objects
print(a is not None)

Dict merge and augmented assign:

left = {"a": 1}
right = {"b": 2}
merged = left | right          # {"a": 1, "b": 2}
left |= {"a": 9}               # left -> {"a": 9}

n = 3
n *= 2                         # 6

⚠️ Pitfalls

• is is not for value equality (except None, True, False, enums).
• Mutable += may mutate in place (list) or rebind (tuple).
• and/or return last evaluated operand — type may not be bool.
• Bitwise & / | on ints ≠ boolean and / or.
• Mixed == across types is usually False (no coercion like JS).

🔗 Related

• Magic methods
• Truthiness
• Walrus
• Conditionals
• Slicing
• Unpacking