Precedence of Python Operators
The combination of values, variables, operators, and function calls is termed as an expression. The Python interpreter can evaluate a valid expression.
For example:
>>> 5 - 7
-2
Here 5 - 7
is an expression. There can be more than one operator in an expression.
To evaluate these types of expressions there is a rule of precedence in Python. It guides the order in which these operations are carried out.
For example, multiplication has higher precedence than subtraction.
# Multiplication has higher precedence
# than subtraction
>>> 10 - 4 * 2
2
But we can change this order using parentheses []
as it has higher precedence than multiplication.
# Parentheses [] has higher precedence
>>> [10 - 4] * 2
12
The operator precedence in Python is listed in the following table. It is in descending order [upper group has higher precedence than the lower ones].
[]
| 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 |
== , != , > , >= , = 2:
print["Lunch being delivered"]
else:
print["Can't deliver lunch"] Output Lunch being delivered This program runs We can get the desired output by using parenthesis
Output Can't deliver lunch Associativity of Python OperatorsWe can see in the above table that more than one operator exists in the same group. These operators have the same precedence. When two operators have the same precedence, associativity helps to determine the order of operations. Associativity is the order in which an expression is evaluated that has multiple operators of the same precedence. Almost all the operators have left-to-right associativity. For example, multiplication and floor division have the same precedence. Hence, if both of them are present in an expression, the left one is evaluated first.
Output 3 0 Note: Exponent operator
We can see that Non associative operatorsSome operators like assignment operators and comparison operators do not have associativity in Python. There are separate rules for sequences of this kind of operator and cannot be expressed as associativity. For example, Furthermore, while chaining of assignments like
Output File "", line 8 x = y = z+= 2 ^ SyntaxError: invalid syntax What is the precedence of operators in Python?Almost all the operators have left-to-right associativity. For example, multiplication and floor division have the same precedence. Hence, if both of them are present in an expression, the left one is evaluated first. Note: Exponent operator ** has right-to-left associativity in Python.
Which operator has the highest precedence []?The logical-AND operator [ && ] has higher precedence than the logical-OR operator [ || ], so q && r is grouped as an operand. Since the logical operators guarantee evaluation of operands from left to right, q && r is evaluated before s-- .
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