Python Greater Than or Equal To

The Python greater than or equal to (left>=right) operator returns True when its left operand is not exceeded by its right operand. When the left operand is smaller than the right operand, the >= operator returns False. For example, 3>=2 and 3>=3 evaluate to True, but 2>=3 evaluates to False.

Examples

Let’s explore a couple of examples regarding the greater than or equal to operator.

Is 3 greater than or equal to 2?

>>> 3 >= 2
True

What about 2 greater than or equal to 3?

>>> 2 >= 3
False

What about 2 greater than or equal to 2?

>>> 2 >= 2
True

Can you compare collections such as lists?

>>> [1, 2] >= [99]
False
>>> [1, 2] >= [0]
True
>>> [1, 2] >= [1, 2, 3]
False
>>> [1, 2] >= [1, 1, 3]
True
>>> [1, 2] >= [1, 2]
True

Yes!

The list “greater than or equal to” operator iterates over the lists and checks pairwise if the i-th element of the left operand is at least as big as the i-th element of the right operand. You can find a detailed discussion on the greater than or equal to operator with list operands below.

Can you use the greater than or equal to operator on custom objects? Yes!

Python Greater Than or Equal to Overload

To use the “greater than or equal to” operator on custom objects, you can use overloading of the __ge__() dunder method (short for: greater than or equal to). The method takes two arguments: self and other and it returns a Boolean value. You can use the arguments’ attributes to determine if one is greater than or equal to the other.

In the following code, you check if a Person is greater than or equal to the other Person by using the age attribute as a decision criterion:

class Person:
    def __init__(self, age):
        self.age = age

    def __ge__(self, other):
        return self.age >= other.age


alice = Person(10)
bob = Person(12)

print(alice >= bob)
# False

print(bob >= alice)
# True

print(bob >= bob)
# True

Because Alice is 10 years old and Bob is 12 years old, the result of alice >= bob is False and bob >= alice is True. If you compare a Person object with itself, the age attribute is equal, so the result will be True.

Python Not Greater Than or Equal

To invert the greater than or equal operator >=, you can use the expression not x >= y with the meaning “smaller than”. So, you can use the expression x < y in most cases. Only if you overload the __ge__ dunder method to define your own “greater than or equal” operator could the semantics between not x>= y and x<y differ.

>>> x = 10
>>> y = 20
>>> not x >= y
True
>>> x < y
True

Python If Statement Greater Than or Equal to

The Python greater than or equal to >= operator can be used in an if statement as an expression to determine whether to execute the if branch or not. For example, the if condition x>=3 checks if the value of variable x is greater than or equal to 3, and if so, enters the if branch.

The following code asks the user to input their age using the input() function. It then checks if the user input, when converted to an integer using int(), is at least 18. If so, it enters the if branch. If not, it enters the else branch.

x = int(input('your age: '))

if x >= 18:
    print('you can vote')
else:
    print('you cannot vote - sorry')

Here’s an example execution of this code where the if branch is entered:

your age: 18
you can vote

Here’s an example execution where the if branch is not entered:

your age: 17
you cannot vote - sorry

Python Chaining Greater Than or Equal

Python allows you to chain the greater than or equal operator. For example, the expression 18 >= x >= 5 would check whether variable x is between 5 and 18, both included. Formally, the expression x >= y >= z is just a shorthand expression for (x >= y) and (y >= z).

Here’s a minimal example that checks if variable x is between 5 and 18 (included).

x = 8

# Is x between 5 and 18?
if 18 >= x >= 5:
    print('yes')

# Output: yes

The code enters the if branch because the if condition is fulfilled.

Python Greater Than or Equal to on Lists

The list “greater than or equal to” operator iterates over the lists and checks pairwise if the i-th element of the left operand is greater than or equal to the i-th element of the right operand.

>>> [1, 2] >= [99]
False
>>> [1, 2] >= [0]
True
>>> [1, 2] >= [1, 2, 3]
False
>>> [1, 2] >= [1, 1, 3]
True
>>> [1, 2] >= [1, 2]
True

• [1, 2] >= [99]. Python first checks 1 >= 99 which is False, so it immediately returns False.
• [1, 2] >= [0]. Python first checks 1 >= 0 which is True.
• [1, 2] >= [1, 2, 3]. Python first compares 1 and 1—a tie! So, it moves on to the second elements 2 and 2—tie again! So, it moves to the third elements as a tie-breaker. But only the second list has a third element so it is considered greater than the first and the result of the operation is False.
• [1, 2] >= [1, 1, 3]. Python compares elements 1 and 1—a tie! But then it compares the second elements 2 and 1 and determines that the first is greater than the second, so the result is True.
• [1, 2] >= [1, 2]. Python first checks 1 >= 1 and then checks 2>=2. Still a tie, so the result is True as they’re equal.

The same method also applies to strings and other sequence types in Python such as tuples.

Is Everything Greater Than or Equal to None?

You cannot use the greater than or equal to operator with None as one of its operands. Python 3 expects that both operands implement the comparable interface, but the None type does not. That’s why Python raises a TypeError if you try to compare variables with None.

>>> 21 >= None
Traceback (most recent call last):
  File "<pyshell#0>", line 1, in <module>
    21 >= None
TypeError: '>=' not supported between instances of 'int' and 'NoneType'

Comparison Operators

Comparison operators are applied to comparable objects and they return a Boolean value (True or False).

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