Operators
Operator Precedence
Python, like other programming languages, follows specific rules for the order in which operations are performed in an expression. This is called operator precedence. Operators with higher precedence are evaluated before operators with lower precedence. When operators have the same precedence, the expression is evaluated from left to right (except for a few exceptions, like exponentiation).
Here’s a table summarizing Python operator precedence (from highest to lowest):
| Precedence | Operator(s) | Description | Associativity |
|---|---|---|---|
| 1 | ** |
Exponentiation | Right-to-left |
| 2 | ~, +, - |
Bitwise NOT, unary plus, unary minus | Right-to-left |
| 3 | *, /, //, % |
Multiplication, division, floor division, modulo | Left-to-right |
| 4 | +, - |
Addition, subtraction | Left-to-right |
| 5 | <<, >> |
Left and right bitwise shifts | Left-to-right |
| 6 | & |
Bitwise AND | Left-to-right |
| 7 | ^ |
Bitwise XOR | Left-to-right |
| 8 | | |
Bitwise OR | Left-to-right |
| 9 | in, not in, is, is not, <, <=, >, >=, !=, == |
Comparisons | Left-to-right |
| 10 | not |
Logical NOT | Right-to-left |
| 11 | and |
Logical AND | Left-to-right |
| 12 | or |
Logical OR | Left-to-right |
Examples:
# Exponentiation has higher precedence than multiplication
result1 = 2 ** 3 * 4 # (2**3) * 4 = 32
# Multiplication has higher precedence than addition
result2 = 2 + 3 * 4 # 2 + (3 * 4) = 14
# Parentheses override precedence
result3 = (2 + 3) * 4 # (2 + 3) * 4 = 20
# Left-to-right associativity for same precedence
result4 = 10 / 2 * 5 # (10 / 2) * 5 = 25
#Demonstrating logical operators precedence
result5 = True and False or True # (True and False) or True = True
result6 = True and (False or True) # True and (False or True) = True
Use of Parentheses:
To ensure a specific order of operations, use parentheses (). Parentheses have the highest precedence.