Python bytes(): Immutable Sequence of Bytes

Python `bytes()`: Immutable Sequence of Bytes

The bytes() function in Python creates an immutable sequence of bytes. It’s widely used for binary data handling, network communication, file I/O, and encryption.

Why Use `bytes()`?

Unlike bytearray(), which is mutable, bytes() objects cannot be changed after creation. This makes them faster and more memory-efficient, especially when working with large binary data that doesn’t need modification.

Syntax

bytes(source, encoding, errors)

source → Initial data (string, list, or integer).
encoding (optional) → Required when converting a string.
errors (optional) → Specifies error handling for encoding.

If no argument is passed, it creates an empty bytes() object (b'').

1. Converting a String to `bytes()`

Common in file operations, APIs, and networking, where data needs to be sent as bytes.

data = bytes("Hello", "utf-8")
print(data)  # Output: b'Hello'

You can’t modify bytes(), but you can decode it back to a string:

print(data.decode())  # Output: Hello

This is useful when handling encoded text in APIs or databases.

2. Creating `bytes()` from a List of Integers

Each number represents a byte (0-255), useful for binary data processing like images or encryption.

binary_data = bytes([65, 66, 67])
print(binary_data)  # Output: b'ABC'

This is helpful in low-level file formats, networking, and cryptography.

3. Using `bytes()` for Fixed-Length Binary Data

If you need a fixed-length binary object (e.g., zero-filled memory for encryption), use:

empty_bytes = bytes(5)  # Creates b'\x00\x00\x00\x00\x00'

This is often used in buffer allocation and low-level system programming.

4. SQL Use Case: Storing Binary Data

Databases often store images, files, or encrypted data as BLOBs (Binary Large Objects).

user_avatar = bytes("image_binary_data", "utf-8")
print(f"INSERT INTO users (profile_picture) VALUES ({user_avatar});")

This ensures efficient storage and retrieval of binary content.

Key Notes

✔ Immutable, unlike bytearray() – great for security & efficiency.
✔ Ideal for handling binary files, encryption, and networking.
✔ Memory-efficient – prevents accidental modification.
✔ Works well with databases & APIs – ensures proper encoding of binary data.

By using bytes(), you can handle binary data safely and efficiently, whether for network protocols, encryption, or file storage. 🚀