Lesson 10: Operator Precedence Rule In Python

Python Operators Precedence Rule

Python uses a rule known as PEMDAS for precedence of operators.

P – Parentheses
E – Exponentiation
M – Multiplication
D – Division
A – Addition
S – Subtraction

The precedence of operators is listed from High to low.

Python Operators Precedence Table

The new Assignment expression (:=) operator from Python 3.8 onwards has the lowest precedence while parentheses() have the highest precedence.

Operator	Desription
:=	Assignment expression (Lowest precedence)
lambda	Lambda expression
if-else	Conditional expression
or	Boolean OR
and	Boolean AND
not x	Boolean NOT
<, <=, >, >=,	Comparison operators
!=, ==	Equality operators
in, not in, is, is not,	Identity operators, membership operators
|	Bitwise OR
^	Bitwise XOR
&	Bitwise AND
<<, >>	Left and right Shifts
+, –	Addition and subtraction
*, @, /, //, %	Multiplication, matrix multiplication, division, floor division, remainder
+x, -x, ~x	Unary plus, Unary minus, bitwise NOT
**	Exponentiation
await x	Await expression
x[index], x[index:index], x(arguments…), x.attribute	Subscription, slicing, call, attribute reference
(expressions…), [expressions…],{key: value…}, {expressions…}	Binding or parenthesized expression, list display, dictionary display, set display
()	Parentheses (Highest precedence)

Example of Python Operators Precedence Rule

10-5 is an expression that contains a single operator.
However, an expression can also contain multiple operators and operands.

Case A
10-5/5
Output will be
9.0

In this expression, the interpreter first divided the 5/5 and then subtracted the result from 10 because, in Python, the division operator has higher precedence than subtraction.

Case B
(10-5)/5
output will be
1.0

Explanation
Here, with the use of parentheses, we force the interpreter to first evaluate the expression inside the parentheses and then continue the overall evaluation.