How to Convert Signed to Unsigned Integer in Python?

Python is a versatile and powerful programming language that has gained immense popularity among developers for its simplicity and readability. With its extensive range of libraries and intuitive syntax, Python has become a go-to choice for various applications, including data analysis, web development, and automation. One of the notable advantages of Python is its ability to handle different data types efficiently.

In this tutorial, we will explore the concept of signed and unsigned integers in Python and discuss why there might be a need to convert between the two. We will walk you through various methods that can be employed to convert signed integers to unsigned integers in Python, providing you with step-by-step instructions and illustrative code examples.

How to Convert signed to unsigned integer in Python

Signed integers are numerical values that can represent both positive and negative numbers. In Python, signed integers are typically stored using the Two's Complement representation. The Two's Complement representation assigns the most significant bit (MSB) as the sign bit, where 0 indicates a positive value, and 1 indicates a negative value. The remaining bits represent the magnitude of the number.

On the other hand, unsigned integers are numbers that can only represent non-negative values. Unlike signed integers, they do not allocate a bit for the sign. As a result, all bits in an unsigned integer are used to represent the magnitude of the number.

Now, let's consider the range of values that signed and unsigned integers can hold. A signed 8-bit integer can hold values from -128 to 127, while a signed 16-bit integer can hold values from -32,768 to 32,767. In contrast, unsigned integers utilize all bits to represent positive values. For instance, an unsigned 8-bit integer can hold values from 0 to 255, and an unsigned 16-bit integer can hold values from 0 to 65,535. As the bit representation increases, the range of values that an unsigned integer can hold also expands.

Method 1: Using the 2**32

In Python, integers are represented using a fixed number of bits, typically 32 bits. To convert a signed integer to its unsigned counterpart, we can simply add 2**32 to the signed integer value. This effectively shifts the signed integer's range into the range of unsigned integers

Now, let's see this method in action with an example. Suppose we have a signed integer, signed_int, with a value of -42. We can convert it to an unsigned integer using the 2**32 method as follows:

signed_int = -42
unsigned_int = signed_int + 2**32

The signed_int variable holds the value -42, and by adding 2**32 to it, we obtain the corresponding unsigned integer value in the range of 0 to 2**32 - 1.

To validate the conversion, let's print the original signed integer and the resulting unsigned integer:

Example

signed_int = -42
unsigned_int = signed_int + 2**32

print("Signed Integer:", signed_int)
print("Unsigned Integer:", unsigned_int)

Output

Signed Integer: -42
Unsigned Integer: 4294967254

As we can see, the signed integer -42 has been successfully converted to its unsigned representation, which is 4294967254 in this case.

Now that we have covered the first method of converting signed integers to unsigned integers using bitwise operations, let's proceed to the next method.

Method 2: Using the Bitwise Left Shift Operator (<<)

The bitwise left shift operation, denoted by the "<<" symbol in Python, shifts the bits of a number to the left by a specified number of positions. Each shift to the left effectively multiplies the number by 2. For example, shifting the bits of the number 5 to the left by 1 position results in 10 (decimal representation). This operation is useful in our conversion process.

Now, let's see this method in action with an example. Let's assume we have a signed integer variable called signed_int with a value of -42. Perform the bitwise left shift operation on the signed integer by the number of bits you want to shift. In this case, we'll use 32 as the number of bits to shift. The formula for the bitwise left shift operation is (signed_int + (1 << 32)).

Example

Here's an example code snippet that demonstrates the conversion process:

signed_int = -42
unsigned_int = signed_int + (1 << 32)

print("Signed Integer:", signed_int)
print("Unsigned Integer:", unsigned_int)

Output

Signed Integer: -42
Unsigned Integer: 4294967254

The output confirms the conversion, showing the originally signed integer as -42 and the corresponding unsigned integer as 4294967254. Remember that the unsigned integer might appear as a large positive number due to the absence of the sign bit.

Using the bitwise left shift method is another approach to converting signed integers to unsigned integers in Python.

Conclusion

In this tutorial, we discussed the concept of signed and unsigned integers in Python and explored methods to convert signed integers to their unsigned counterparts. By understanding the differences between signed and unsigned integers and mastering techniques such as using the 2**32 method and the bitwise left shift operator, we can confidently handle scenarios that require unsigned integer representations.