How to Convert a Hexadecimal String to an Integer in Python?

In Python, you can use the int() method (with a base 16 as the second argument) to convert (uppercase or lowercase) hexadecimal string to its integer equivalent, for example, like so:

num = int('ddd5', 16)

print(num) #=> 56789

num = int('DDD5', 16)

print(num) #=> 56789

This also works with hexadecimal strings that have the "0x" (or "0X") hexadecimal radix prefix:

# Python 2.6+
num = int('0xddd5', 16)

print(num) #=> 56789

# Python 2.6+
num = int('0Xddd5', 16)

print(num) #=> 56789

Specifying an invalid hexadecimal number would raise the following error:

// ValueError: invalid literal for int() with base 16: '0o30071'
int('0o30071', 16)

If the hexadecimal string has 0x (or 0X) radix prefix, then you may also specify 0 as the second argument (i.e. the base) to the int() method, which would make it infer the value:

# Python 2.6+
num = int('0xddd5', 0)

print(num) #=> 56789

This could be useful, for example, if a variable with a number can be of different types (such as binary, octal, hexadecimal, etc.).