Python hex() Function

The hex() function in Python is used to convert an integer number to a hexadecimal string (base 16), prefixed with 0x.

This is useful when working with colors, memory addresses, or binary data formats.

Syntax

hex(number)

Parameters:

• number – A valid integer (positive or negative)

Returns:

• A string starting with '0x' followed by the hexadecimal equivalent of the integer.

Example: Convert Positive Integer to Hex

print(hex(255))

0xff

Example: Convert Negative Integer to Hex

print(hex(-42))

-0x2a

Use Case: RGB Colors in Web Design

Each color component in an RGB color code is often represented in hexadecimal:

r = 255
g = 165
b = 0

hex_color = f"#{hex(r)[2:]}{hex(g)[2:]}{hex(b)[2:]}"
print(hex_color)

#ffa500

Note: [2:] is used to remove the '0x' prefix.

Common Mistakes

• Passing a float: hex(3.14) will raise TypeError
• Passing a string: hex("10") is invalid
• Always pass an integer type: use int() if needed

Interview Tip

In interviews, hex() is often used in bit manipulation or encoding problems. Know how to combine it with int(), bin(), or ord().

Summary

• hex() converts an integer to a base-16 (hexadecimal) string
• Output starts with '0x' for positive or '-0x' for negative
• Does not work on float or string types directly

Practice Problem

Write a program that reads an integer from the user and prints its hexadecimal equivalent.

num = int(input("Enter an integer: "))
print("Hexadecimal:", hex(num))