PythonVariables and Data TypesBinary Data type

Binary Data Type in Python

Python provides special data types to handle binary data such as bytes, byte arrays, and memory views. These are useful when working with files, network streams, images, and other non-text data.

The main binary data types in Python are:

  • bytes
  • bytearray
  • memoryview

Key Characteristics

Data TypeMutabilityUsage
bytesImmutableRead-only binary sequences
bytearrayMutableModifiable binary sequences
memoryviewViewEfficient memory access to binary data

Creating bytes

binary_bytes.py
# Create bytes from string
b1 = b"Hello"
 
# Using bytes() constructor
b2 = bytes([65, 66, 67])   # ASCII codes for 'A', 'B', 'C'
 
print(b1)
print(b2)
output.txt
b'Hello'
b'ABC'

Explanation:

  • Prefix b creates a byte literal.
  • The bytes() constructor can take an iterable of integers (0-255) and returns a bytes object.

Example 1: Indexing and Slicing Bytes

binary_bytes_slice.py
b = b"Python"
 
print(b[0])         # First byte (as integer)
print(b[1:4])       # Slice
output.txt
80
b'yth'

Explanation:

  • Bytes are indexed like strings, but individual elements are integers (byte values).
  • Slicing returns another bytes object.

Creating bytearray

binary_bytearray.py
# Mutable binary data
ba = bytearray(b"Data")
 
# Modify in-place
ba[0] = 100   # 'd'
 
print(ba)
print(ba.decode())   # Convert to string
output.txt
bytearray(b'data')
data

Explanation:

  • bytearray is a mutable version of bytes.
  • It supports in-place modification and has most methods of lists and strings.

Example 2: Using memoryview

binary_memoryview.py
data = bytearray(b"example")
mv = memoryview(data)
 
print(mv[0])          # First byte
print(bytes(mv[1:4])) # Slice as bytes
output.txt
101
b'xam'

Explanation:

  • memoryview allows zero-copy access to binary data.
  • Useful when dealing with large datasets or performance-critical applications.

Example 3: Reading Binary Files

binary_file_read.py
# Open file in binary mode
with open("image.png", "rb") as f:
    content = f.read(10)
 
print(content)
output.txt
b'\x89PNG\r\n\x1a\n\x00\x00'

Explanation:

  • Mode 'rb' means read binary.
  • The file is read as raw bytes — useful for images, audio, etc.

Common Use Cases

  • File I/O for binary files (images, audio, compressed formats)
  • Network programming (sending/receiving binary packets)
  • Data serialization (pickle, JSON with binary attachments)
  • Low-level protocols (custom protocols, device communication)

Summary

  • Python provides bytes, bytearray, and memoryview to work with binary data.
  • bytes is immutable, bytearray is mutable, memoryview allows efficient views.
  • Binary data types are essential for working with files, streams, and low-level programming.

Next, we will cover Special Data Types in Python — which includes types like NoneType and others that provide unique functionality in your programs.

Boolean Data typeSpecial Data type