How to check if a float value is a whole number in Python?

To check if a float value is a whole number in Python, you can use several methods. The most straightforward approach is using the is_integer() method available for float objects.

Using the is_integer() Method

The is_integer() method returns True if the float value represents a whole number, otherwise False ?

print((10.0).is_integer())
print((15.23).is_integer())
print((-5.0).is_integer())
print((0.0).is_integer())

True
False
True
True

Using Modulo Operation

You can also check if a float is a whole number by using the modulo operator to see if there's no remainder when divided by 1 ?

def is_whole_number(num):
    return num % 1 == 0

print(is_whole_number(7.0))
print(is_whole_number(7.5))
print(is_whole_number(-3.0))

True
False
True

Using int() Conversion

Another approach is to compare the float with its integer conversion ?

def is_whole_number(num):
    return num == int(num)

print(is_whole_number(12.0))
print(is_whole_number(12.7))
print(is_whole_number(-8.0))

True
False
True

Comparison of Methods

Conclusion

The is_integer() method is the most Pythonic way to check if a float is a whole number. Use modulo or int conversion for custom functions or when working with different numeric types.