Python Binary Files Tutorial – Complete Guide

Welcome to another insightful tutorial where we’ll dive into the world of Python binary files. As an integral part of Python, understanding binary files can help you significantly boost your programming skills, increase the performance of your application, and efficiently store data. Regardless of your coding experience, this guide will lead you through the fundamentals of binary files in Python, with plenty of examples along the way.

What are Python Binary Files?

Binary files in Python are files that store data in a format that’s not meant for human interpretation. They contain binary data, which is essentially a sequence of bytes. Unlike text files, binary files keep data in a sequence of 0 and 1, allowing efficient storage and seamless data transfer between different platforms.

What’s the Purpose of Python Binary Files?

Python binary files offer an array of benefits for developers across various domains. Here are a few reasons why you should learn about Python binary files:

  • Binary files consume lesser space, leading to resource efficiency.
  • These files can effectively store complex data like images, audio files, and videos.
  • Handling large amounts of data becomes more manageable with binary files.
  • Binary files ensure faster reading and writing operations, enhancing application performance.

Why Should You Learn It?

Every budding programmer or seasoned developer should learn about Python binary files. It’s not just about mastering a new tool; it’s about empowering yourself with a versatile skill that can help you handle complex programming problems, capably work with various data formats, and develop more efficient and performant applications.

A strong understanding of binary files in Python can open up new opportunities – whether you aim to build a resource-intensive game, deal with multimedia applications, or strive to optimize your data operations. Grasping this concept definitely adds a feather to your Python expertise cap!

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Python Binary Files: Writing Operations

Before we dive into the examples, let’s revisit some basics. In Python, to write binary data, we use the `wb` mode with the `open()` function. This mode stands for “write binary”. Let’s dive in:

Writing integers to a file

# Let's define an integer
num = 15 
# open file in binary mode
with open('example.bin', 'wb') as file:
    file.write(num.to_bytes(2, 'big'))

Here, we’re defining an integer and writing it to a file named ‘example.bin’. We use the `to_bytes()` method to convert the integer into bytes. The ‘big’ keyword represents that it is big-endian encoded.

Writing strings to a file

# Let's define a string
str = "Hello, Zenva"
# open file in binary mode
with open('example.bin', 'wb') as file:

In this example, we’re converting a string to bytes using `encode(‘UTF-8’)` method and writing it to the same binary file.

Python Binary Files: Reading Operations

To read binary data, use the `rb` mode, which stands for “read binary”. Let’s explore with a few examples.

Reading integers from a file

# open file in binary mode
with open('example.bin', 'rb') as file:
    byte =
    number = int.from_bytes(byte, 'big')

In the above example, we read an integer from the binary file using the `from_bytes()` method to convert bytes back to an integer.

Reading strings from a file

# open file in binary mode
with open('example.bin', 'rb') as file:
    bytes =
    str = bytes.decode('UTF-8')

In this example, we read a string from the binary file. We use the `decode(‘UTF-8’)` method to convert bytes back to a string.

Other Operations on Python Binary Files

To work with binary files in Python more effectively, you need to understand other operations such as appending to a binary file, updating a binary file and working with byte arrays.

Appending to a Binary File

If you wish to add data to an existing binary file without overwriting its contents, you can use the ‘ab’ (append binary) mode.

# Define some data
data = b'Zenva Coding Academy'
# Open file in 'ab' mode
with open('example.bin', 'ab') as file:

Updating a Binary File

The ‘r+b’ mode allows you to read and write (update) a binary file:

# Open file in 'r+b' mode
with open('example.bin', 'r+b') as file: 
    file.write(b'Updated Content')

In this example, we first move the pointer to the start of the file with the `seek(0)` method, and then write the new content to the file.

Working with Byte Arrays

Byte arrays are mutable sequences of integers in the range 0 <= x < 256. They can be manipulated byte by byte.

# Create an empty byte array
array = bytearray(4)

This code will print an array of 4 zeroes since we haven’t initialized the byte array with any value.

# Create a byte array from a binary string
array = bytearray(b'Zenva')

In the above example, we initialize the byte array with the binary value of the string ‘Zenva’.

# Modify a byte in the array
array = bytearray(b'Zenva')
array[0] = 97

Here, we modify the first byte in the array to be 97 (‘a’ in ASCII) and print the updated array.

Remember, working with Python binary files is all about understanding and manipulating bytes. These examples should give you a headstart. Keep experimenting and discovering more as you code. Happy Coding from us at Zenva!

Where to Go Next? How to Keep Learning?

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Exploring the fundamentals of Python binary files is merely scratching the surface of what you can achieve with Python. This dynamic language can open up new realms in game development, artificial intelligence, data science, web development, and much more. But to gain the true value of Python and chalk out a successful career pathway, consistent learning is key.

At Zenva, we have bid goodbye to one-size-fits-all training and embraced personalized, interactive, and flexible learning with our Python Mini-Degree. Join us to dive deeper into the world of Python, get hands-on coding experience, and stay ahead of the game in the evolving tech landscape. Let’s transform you from a Python beginner to a proficient developer! Your coding adventure starts here. Happy learning!

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