Python not equal operator

In this post, we will see about Python not equal operator.

Not equal operator is denoted by != in Python and returns true when two variables are of same type but have different value. If two variable posses same value, then not equal operator will return False.
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Python not equal operator example

Here is simple example of non equal operator

print(2.2!=2)

This will print True.

str1 = "world"
str2 = "world"
str3 = "WORLD"

print(str1!=str2)
print(str1!=str3)

Output:

str1!=str2 returns False:
As str1 and str2 are exactly same String, so it return False.

str1!=str3 returns True:
As str1 and str3 differ in case, it return True.

Please note that you can use <> for not equal in Python 2 but <> is deprecated in Python 3.

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Python not equal operator in case of Custom object

When you call !=, python internally calls ne(self, other) method. In case of custom objects, you can implement your own version in the class.

Here is quick example.

class Country:
    name = ''
    population = 0

    def __init__(self, name, population):
        self.name = name
        self.population = population

    def __ne__(self, other):
        # If different type, you can return true
        if type(other) != type(self):
            return True
        if self.name != other.name:
            return True
        else:
            return False

india1 = Country('India', 1000)
india2 = Country('India', 2000)
china = Country('China', 3000)

print(india1 != india2)
print(india1 != china)

Output:

As you can see, we have implemented ne(self, other) and two countries are not equal, if there name are not same.

So that’s why
india1 != india2 returned False as name is same in both objects even though population is different.

That’s all about Python not equal operator.