Convert a hex string to an integer in Python

This post will discuss how to convert a hex string to an integer in Python.

1. Using `int` constructor

The int constructor int() can be used for conversion between a hex string and an integer. The int constructor takes the string and the base you are converting from. The following program demonstrates this:

if __name__ == '__main__':

s = "0x64" # With 0x prefix

x = int(s, 16)

print(x) # 100

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This also works without the 0x prefix:

if __name__ == '__main__':

s = "64" # Without 0x prefix

x = int(s, 16)

print(x) # 100

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If the base of 0 is specified, we’ll infer the base from the string’s prefix. To distinguish between the hex string and decimal string, prefix your string with 0x.

if __name__ == '__main__':

s = "0x64" # With 0x prefix

x = int(s, 0)

print(x) # 100

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2. Using `ast.literal_eval()` function

Another option is to use the ast.literal_eval() function to evaluate strings safely, as shown below. Note this won’t work without the 0x prefix:

import ast

if __name__ == '__main__':

s = "0x64"

x = ast.literal_eval(s)

print(x) # 100

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That’s all about converting a hex string to an integer in Python.

Convert a hex string to an integer in Python

1. Using int constructor

2. Using ast.literal_eval() function

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1. Using `int` constructor

2. Using `ast.literal_eval()` function