Problem Formulation
If you print a hexadecimal number, Python uses the prefix '0x' to indicate that it’s a number in the hexadecimal system and not in the decimal system like normal integers.
print(hex(42)) # 0x2a
However, if you already know that the output numbers are hexadecimal, you don’t necessarily need the '0x' prefix.
How to print hex numbers without the '0x' prefix?
Method 1: Slicing
To skip the prefix, use slicing and start with index 2 on the hexadecimal string. For example, to skip the prefix '0x' on the result of x = hex(42) ='0x2a', use the slicing operation x[2:] that results in just the hexadecimal number '2a' without the prefix '0x'.
x = hex(42) print(x) # 0x2a print(x[2:]) # 2a
Feel free to dive into the hex() built-in function in this video tutorial:
But what if you actually want to replace the prefix '0x' with the prefix '00' so that the resulting string has the same length?
Method 2: Slicing + zfill()
The Python string.zfill() method fills the string from the left with '0' characters. In combination with slicing from the third character, you can easily construct a hexadecimal string without leading '0x' characters and with leading '0' characters up to the length passed into the string.zfill(length) method.
print(hex(42)[2:].zfill(4)) # 002a
Alternatively, if you want to create a string with 8 characters, use string.zfill(8):
print(hex(42)[2:].zfill(8)) # 0000002a
You can learn more about zfill() in this video about Python string methods:
Method 3: Negative Hex Numbers
If you need to handle negative hexadecimal numbers, the above methods do not work because the hex number now needs to replace the second and third character '0x'. For example, the hexadecimal number hex(-42) is '-0x2a'. You cannot simply skip the first two characters to obtain the correct result, can you? At the same time, if you always skipped or replaced the second and third characters, it wouldn’t work for positive numbers either. So what to do?
To print a positive or negative hexadecimal without the '0x' or '-0x' prefixes, you can simply use the string.replace('x', '0') method and replace each occurrence of 'x' with '0'. The resulting string is mathematically correct because leading '0's don’t change the value of the number.
# Negative Hexadecimal
print(hex(-42).replace('x', '0'))
# -002a
# Positive Hexadecimal
print(hex(42).replace('x', '0'))
# 002a
Where to Go From Here?
Enough theory. Let’s get some practice!
Coders get paid six figures and more because they can solve problems more effectively using machine intelligence and automation.
To become more successful in coding, solve more real problems for real people. That’s how you polish the skills you really need in practice. After all, what’s the use of learning theory that nobody ever needs?
You build high-value coding skills by working on practical coding projects!
Do you want to stop learning with toy projects and focus on practical code projects that earn you money and solve real problems for people?
🚀 If your answer is YES!, consider becoming a Python freelance developer! It’s the best way of approaching the task of improving your Python skills—even if you are a complete beginner.
If you just want to learn about the freelancing opportunity, feel free to watch my free webinar “How to Build Your High-Income Skill Python” and learn how I grew my coding business online and how you can, too—from the comfort of your own home.
Programming Humor
