Precedence of Python Operators

 

Precedence of Python Operators

An expression is a collection of numbers, variables, operations, and built-in or user-defined function calls. The Python interpreter can evaluate a valid expression

Code

1. 2 - 7  

Output:

-5

The expression 2 - 7 is used as an example here. In an expression, we can add multiple operators. There is a principle of precedence in Python for evaluating these types of expressions. It directs the sequence in which certain tasks are completed.

Division, for instance, takes precedence over addition.

Code

1. # Division has higher precedence than addition  
2. 16 + 16 / 2  

Output:

24.0

However, we can reverse this sequence by employing parenthesis (), which takes precedence over division.

Code

1. # Parentheses () holds higher precedence  
2. (16 + 16) / 2  

Output:

16.0

The following table shows the precedence of Python operators. It's in reverse order (the upper operator holds higher precedence than the lower operator).

Operators	Meaning
()	Parentheses
**	Exponent
+x, -x, ~x	Unary plus, Unary minus, Bitwise NOT
*, /, //, %	Multiplication, Division, Floor division, Modulus
+, -	Addition, Subtraction
<<, >>	Bitwise shift operators
&	Bitwise AND
^	Bitwise XOR
|	Bitwise OR
==, !=, >, >=, <, <=, is, is not, in, not in	Comparisons, Identity, Membership operators
not	Logical NOT
and	Logical AND
or	Logical OR

Consider the following examples:

Assume we're building an if...else block that only executes if the color is red or green and quantity is greater than or equal to 5.

Code

1. # Precedence of and and or operators  
2. colour = "red"  
3.   
4. quantity = 0  
5.   
6. if colour == "red" or colour == "green" and quantity >= 5:  
7.     print("Your parcel is dispatched")  
8. else:  
9.     print("your parcel cannot be dispatched")  

Output:

Your parcel is dispatched

Even though quantity is 0, this program runs if block. Because and takes precedence over or does not produce the anticipated result.