# Bitwise XOR of Hex Numbers in Python

The main aim of this article is to demonstrate how to work with XOR numbers in a hexadecimal number system in Python.

## Bitwise XOR of Hex Numbers in Python

XOR is a bitwise operator, which means Exclusive OR. It performs the logical operation where if both inputs (either 0 or 1) are the same, then it returns 1; otherwise, if the input numbers are different (like 0 and 1 or 1 and 0), then the output will be 0.

XOR is normally used in applications used for compression, encryption, graphics, or communication in any form. Being a part of the Bitwise logical operators, XOR allows greater precision and requires fewer resources, thus making the code much faster and more efficient.

Using the `^`

operator, it is fairly easy to XOR numbers in decimals. What about numbers that are initially in or part of a string?

Consider the following code:

```
def strxor(a, b):
if len(a) > len(b):
return "".join(["%s" % (ord(x) ^ ord(y)) for (x, y) in zip(a[:len(b)], b)])
else:
return "".join(["%s" % (ord(x) ^ ord(y)) for (x, y) in zip(a, b[:len(a)])])
if __name__ == '__main__':
print("1C2 ^ ABC = ", strxor("1C2", "ABC"))
print("2FF ^ 78B = ", strxor("2FF", "78B"))
print("29A ^ 90C = ", strxor("29A", "90C"))
print("10C ^ 24B = ", strxor("10C", "24B"))
print("BAD ^ 432 = ", strxor("BAD", "432"))
print("54F ^ 123 = ", strxor("54F", "123"))
```

This gives the output below:

```
1C2 ^ ABC = 1121113
2FF ^ 78B = 51264
29A ^ 90C = 1192
10C ^ 24B = 341
BAD ^ 432 = 118114118
54F ^ 123 = 46117
```

Let us verify our solution:

```
if __name__ == '__main__':
print("1C2 ^ 0xABC = ", 0x1C2 ^ 0xABC)
print("2FF ^ 0x78B = ", 0x2FF ^ 0x78B)
print("29A ^ 0x90C = ", 0x29A ^ 0x90C)
print("10C ^ 0x24B = ", 0x10C ^ 0x24B)
print("BAD ^ 0x432 = ", 0xBAD ^ 0x432)
print("54F ^ 0x123 = ", 0x54F ^ 0x123)
```

This gives the following output:

```
1C2 ^ 0xABC = 2942
2FF ^ 0x78B = 1396
29A ^ 0x90C = 2966
10C ^ 0x24B = 839
BAD ^ 0x432 = 3999
54F ^ 0x123 = 1132
```

As seen from the code above, we have created a new method named `strxor`

, which takes two parameters named `a`

and `b`

corresponding to the two strings passed to the function. The objective of the method is to take two strings, XOR them, and return the result (which also is a string).

Upon verification of the solution, it is seen that the result is different from what was expected. In other words, the implemented function `strxor`

has a logical error.

The solution to this problem can be approached in multiple ways. Some of these are defined as follows:

### Solution 1

```
def strxor(a, b):
if len(a) > len(b):
res = "".join(["%x" % (int(x,16) ^ int(y,16)) for (x, y) in zip(a[:len(b)], b)])
return int("0x" + res, 0)
else:
res = "".join(["%x" % (int(x,16) ^ int(y,16)) for (x, y) in zip(a, b[:len(a)])])
return int("0x" + res, 0)
```

This gives the following output:

```
1C2 ^ ABC = 2942
2FF ^ 78B = 1396
29A ^ 90C = 2966
10C ^ 24B = 839
BAD ^ 432 = 3999
54F ^ 123 = 1132
```

In the solution mentioned above, fixes were made to the original function to show the correct output upon inspecting what was changed in the code instead of using `ord()`

, which returns the number representing the Unicode code of a specified character.

We use int with the parameters being one of the strings and a 16, referring to the base of the number corresponding to hex.

### Solution 2

```
def strxor(a, b):
if len(a) > len(b):
res = '%x' % (int(a[:len(b)],16)^int(b,16))
return int("0x" + res, 0)
else:
res = '%x' % (int(a,16)^int(b[:len(a)],16))
return int("0x" + res, 0)
```

This gives the following output:

```
1C2 ^ ABC = 2942
2FF ^ 78B = 1396
29A ^ 90C = 2966
10C ^ 24B = 839
BAD ^ 432 = 3999
54F ^ 123 = 1132
```

This method does not rely on `for`

loops and `zip`

. It is much faster than its counterpart regarding runtime and overall execution time.

**Salman Mehmood**

Hello! I am Salman Bin Mehmood(Baum), a software developer and I help organizations, address complex problems. My expertise lies within back-end, data science and machine learning. I am a lifelong learner, currently working on metaverse, and enrolled in a course building an AI application with python. I love solving problems and developing bug-free software for people. I write content related to python and hot Technologies.

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