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Python Not Equal

Python Not Equal is a Comparison Operator used to check if two values are not equal.

The symbol used for Python Not Equal operator is !=. There should be no separator between exclamatory symbol and equal symbol. ! is referred to as not.

Not Equal Operator is mostly used in boolean expressions of conditional statements like If, If-Else, Elif, While, etc.

Syntax

Following is the syntax of Python Not Equal comparison operator.

result = operand_1 != operand_2

where operand_1 and operand_2 are values of any datatype.

Not Equal operator returns a boolean value. The operator returns True if operand_1 and operand_2 are not equal values, else it returns False.

Example 1: Not Equal Comparison Operator

In this example, we shall take two integers, and check if they are not equal using !=.

Python Program

a = 10 b = 12 c = 12 print(a != b) print(b != c)

a and b are not equal and therefore a != b returned True.

a and c are equal and therefore a != b returned False.

Example 2: Not Equal Operator with IF Statement

We already know that not equal operator returns a boolean value. Therefore, this can be used in conditions of decision making statements.

In the following example, we shall use not equal operator in IF statement condition.

Python Program

a = 11 if a%2 != 0 : print(a, "is not even number.")

a%2 != 0 returns True for a=11. And therefore, if block is executed.

Example 3: Not Equal Operator with Strings

In this example, we shall use Not Equal operator to check if two strings are not equal.

Python Program

a = "python" b = "javascript" if a != b : print(a, 'and', b, 'are different.')

Clearly, the two strings are not equal and the result of a != b is True. So, Python executes the if block code.

Example 4: Not Equal Operator in While Condition

You can use not equal operator in while loop condition.

Python Program

a = 4 while a != 0 : print("hello") a -= 1

Example 5: Not Equal Operator in Compound Condition

not equal operator can be used to combine simple conditions and form compound conditions or boolean expressions.

Python Program

a = 4 b = 5 if (a == 1) != (b == 5): print('Hello')

(a == 1) and (b == 5) two simple conditions and we have use not equal operator to join them and form a compound condition.

Summary

In this tutorial of Python Examples, we learned what Python Not Equal Comparison Operator is, how to use it to find if two values are not equal, with the help of well detailed example programs.

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Python not equal operator

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Python not equal operator returns True if two variables are of same type and have different values, if the values are same then it returns False . Python is dynamic and strongly typed language, so if the two variables have the same values but they are of different type, then not equal operator will return True .

Python not equal operators

Operator	Description
!=	Not Equal operator, works in both Python 2 and Python 3.
<>	Not equal operator in Python 2, deprecated in Python 3.

Python 2 Example

$ python2.7 Python 2.7.10 (default, Aug 17 2018, 19:45:58) [GCC 4.2.1 Compatible Apple LLVM 10.0.0 (clang-1000.0.42)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> 10 <> 20 True >>> 10 <> 10 False >>> 10 != 20 True >>> 10 != 10 False >>> '10' != 10 True >>> 

Python 3 Example

$ python3.7 Python 3.7.0 (v3.7.0:1bf9cc5093, Jun 26 2018, 23:26:24) [Clang 6.0 (clang-600.0.57)] on darwin Type "help", "copyright", "credits" or "license" for more information. >>> 10 <> 20 File "", line 1 10 <> 20 ^ SyntaxError: invalid syntax >>> 10 != 20 True >>> 10 != 10 False >>> '10' != 10 True >>> 

We can use Python not equal operator with f-strings too if you are using Python 3.6 or higher version.

x = 10 y = 10 z = 20 print(f'x is not equal to y = ') flag = x != z print(f'x is not equal to z = ') # python is strongly typed language s = '10' print(f'x is not equal to s = ') 

x is not equal to y = False x is not equal to z = True x is not equal to s = True 

Python not equal with custom object

When we use not equal operator, it calls __ne__(self, other) function. So we can define our custom implementation for an object and alter the natural output. Let’s say we have Data class with fields — id and record. When we are using the not-equal operator, we just want to compare it for record value. We can achieve this by implementing our own __ne__() function.

class Data: record = '' def __init__(self, i, s): self.id = i self.record = s def __ne__(self, other): # return true if different types if type(other) != type(self): return True if self.record != other.record: return True else: return False d1 = Data(1, 'Java') d2 = Data(2, 'Java') d3 = Data(3, 'Python') print(d1 != d2) print(d2 != d3) 

Notice that d1 and d2 record values are same but “id” is different. If we remove __ne__() function, then the output will be like this:

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