How to Split a Large File into Fixed-Size Parts in Python

import os
import math

def split_file(filepath, chunk_size_bytes):
    """Split a file into parts of fixed size (bytes). Creates part files in same directory."""
    filepath = os.path.abspath(filepath)
    basename = os.path.basename(filepath)
    file_size = os.path.getsize(filepath)
    num_parts = math.ceil(file_size / chunk_size_bytes)
    
    with open(filepath, 'rb') as f:
        for part_num in range(num_parts):
            chunk = f.read(chunk_size_bytes)
            part_filename = f"{basename}.part{part_num + 1:03d}"
            with open(part_filename, 'wb') as part_file:
                part_file.write(chunk)
            print(f"Created {part_filename} ({len(chunk)} bytes)")

if __name__ == "__main__":
    # Example: split a sample file into 16-byte chunks
    sample = "example_data.txt"
    with open(sample, 'w') as f:
        f.write("Hello world, this is a test file for splitting.")
    
    split_file(sample, 16)
    
    # Cleanup after demonstration
    for fname in os.listdir('.'):
        if fname.startswith(sample) and fname != sample:
            os.remove(fname)
    os.remove(sample)