Python hex()

Summary: in this tutorial, you’ll learn how to use the Python hex() function to convert an integer number to a lowercase hexadecimal string prefixed with 0x.

Introduction to the Python hex() function #

The hex() function accepts an integer and converts it to a lowercase hexadecimal string prefixed with 0x.

Here’s the syntax of the hex() function:

hex(x)

The following example uses the hex() function to convert x from an integer (10) to a lowercase hexadecimal string prefixed with 0x:

x = 10
result = hex(10)
print(result)  # ? 0xa
print(type(result))  # ? <class 'str'>Code language: PHP (php)

If x is not an integer, it needs to have an __index__() that returns an integer. For example:

class MyClass:
    def __init__(self, value):
        self.value = value

    def __index__(self):
        return self.value


result = hex(MyClass(10))
print(result) # ? 0xa

Output:

0xa

How it works.

• First, define the MyClass class with a value attribute.
• Second, initialize the value in the __init__() method.
• Third, implement the __index__() method that returns the value.
• Finally, create a new instance of MyClass and pass it to the hex() function.

Another way to convert an integer to an uppercase or lower hexadecimal string is to use f-strings with a format. For example:

a = 10
h1 = f'{a:#x}'
print(h1)  # ? 0xa

h2 = f'{a:x}'
print(h2)  # ? a

h3 = f'{a:#X}'
print(h3)  # ? 0XA

h3 = f'{a:X}'
print(h3)  # ? ACode language: PHP (php)

Summary #

• Use the Python hex() function to convert an integer to a lowercase hexadecimal string prefixed with 0x.