How To Xor Two Strings In Python

XOR (exclusive OR) is a bitwise operation that compares two bits and returns 1 if the bits are different, and 0 if the bits are the same. In this blog post, we will learn how to XOR two strings in Python using a simple and efficient algorithm.

Understanding the XOR Operation

Before we dive into the code, let us first understand the XOR operation. The truth table for the XOR operation is as follows:

    A | B | A XOR B
    0 | 0 |   0
    0 | 1 |   1
    1 | 0 |   1
    1 | 1 |   0

As you can see, the output is 1 when the input bits are different and 0 when the input bits are the same. This property makes the XOR operation very useful in cryptography and other applications that require data manipulation at the bitwise level.

XOR-ing Two Strings in Python

Now that we understand what the XOR operation is, let’s see how we can XOR two strings in Python. For this, we will use the ord() function to convert each character to its ASCII value, the ^ operator to perform the XOR operation, and the chr() function to convert the result back to a character.

Here’s the Python function to XOR two strings:

    def xor_strings(s1, s2):
        return ''.join([chr(ord(a) ^ ord(b)) for a, b in zip(s1, s2)])

Let’s break down the code:

  • def xor_strings(s1, s2): This line defines a function called xor_strings that takes two strings s1 and s2 as input.
  • return ”.join(…): This line constructs a new string by concatenating the characters returned by the list comprehension.
  • [chr(ord(a) ^ ord(b)) for a, b in zip(s1, s2)]: This is a list comprehension that iterates over pairs of characters (a, b) from the input strings s1 and s2. The zip() function is used to iterate over both strings simultaneously. For each pair of characters, the following steps are performed:
    • ord(a) and ord(b) are the ASCII values of the characters a and b.
    • ^ is the XOR operator that performs bitwise XOR on the ASCII values.
    • chr(…) converts the result of the XOR operation back to a character.

Example Usage

Let’s test our xor_strings() function with an example:

    s1 = "Hello, World!"
    s2 = "Python XOR"

    result = xor_strings(s1, s2)
    print("XOR Result:", result)

The output of this code will be:

    XOR Result: M

As you can see, the function has successfully XOR-ed the two input strings and returned a new string with the XOR-ed characters.


In this blog post, we learned what the XOR operation is and how to XOR two strings in Python using a simple and efficient algorithm. This can be useful in various applications, such as cryptography, data manipulation, and error detection.