File Splitter Program in Python

 File Splitter Program in Python

A Python file splitter is a coding program that converts a big file into smaller chunks or "chunks," depending on its size. This can be helpful when splitting large files for more straightforward storage, transmission, or processing. The split files can then be reunited if necessary. In Python, this is often accomplished by reading the file in chunks and writing every chunk to a new file with an incrementing name.

Full Code with Explanation:

Python Code

import os

def split_file(file_path, chunk_size):
    """
    Split a file into smaller parts based on the specified chunk size.
    
    Args:
        file_path (str): Path to the input file.
        chunk_size (int): Size of each output file in bytes.
    """
    # Check if the file exists
    if not os.path.isfile(file_path):
        print(f"Error: File '{file_path}' does not exist.")
        return
    
    # Validate chunk size
    if chunk_size <= 0:
        print("Error: Chunk size must be a positive number.")
        return
    
    # Get the file size for progress tracking
    file_size = os.path.getsize(file_path)
    base_name = os.path.splitext(file_path)[0]  # Extract base name without extension
    
    # Open the input file in binary read mode
    with open(file_path, 'rb') as f:
        part_num = 1  # Part counter
        bytes_processed = 0  # Track progress
        
        # Read and split the file into chunks
        while True:
            chunk = f.read(chunk_size)  # Read a chunk
            if not chunk:  # If no more data, exit loop
                break
            
            # Create output file name
            output_file = f"{base_name}_part{part_num}"
            
            # Write the chunk to a new file
            with open(output_file, 'wb') as out_f:
                out_f.write(chunk)
            
            # Update progress
            bytes_processed += len(chunk)
            print(f"Created: {output_file} ({bytes_processed}/{file_size} bytes processed)")
            part_num += 1
    
    print("File splitting completed successfully!")

def main():
    """Main function to handle user input and run the splitter."""
    # Get file path from user
    file_path = input("Enter the path to the file you want to split: ")
    
    # Get chunk size from user with error handling
    try:
        chunk_size = int(input("Enter the chunk size (in bytes): "))
        split_file(file_path, chunk_size)
    except ValueError:
        print("Error: Please enter a valid number for chunk size.")

if __name__ == "__main__":
    main()

Step-by-Step Explanation of the Code

1. Import os Module

Python Code

import os

os is used for file operations like checking existence (os.path.isfile) and getting file size (os.path.getsize).

2. Define the split_file Function

Python Code

def split_file(file_path, chunk_size):

Takes two parameters: the file path and the desired chunk size in bytes.

3. Error Handling

Python Code

    
if not os.path.isfile(file_path):
    print(f"Error: File '{file_path}' does not exist.")
    return
if chunk_size <= 0:
    print("Error: Chunk size must be a positive number.")
    return
    

Checks if the file exists and if the chunk size is valid.

4. Setup for Splitting

file_size: Used for progress tracking. base_name: Extracts the file name without extension (e.g., myfile from myfile.txt).

5. Read and Split the File

Opens the file in binary read mode (rb). Reads chunk_size bytes at a time in a loop until no data remains (chunk is empty).

6. Write Chunks to New Files

Python Code

output_file = f"{base_name}_part{part_num}"
with open(output_file, 'wb') as out_f:
    out_f.write(chunk)

Names each part (e.g., myfile_part1, myfile_part2). Writes the chunk to a new file in binary write mode (wb).

7. Progress Feedback

Python Code

bytes_processed += len(chunk)
print(f"Created: {output_file} ({bytes_processed}/{file_size} bytes processed)")
part_num += 1

Updates the number of bytes processed and increments the part number.

8. User Interaction in main

Python Code

def main():
    file_path = input("Enter the path to the file you want to split: ")
    try:
        chunk_size = int(input("Enter the chunk size (in bytes): "))
        split_file(file_path, chunk_size)
    except ValueError:
        print("Error: Please enter a valid number for chunk size.")

9. Run the Script

Python Code

if __name__ == "__main__":
    main()

How to Use It

1. Save the code as file_splitter.py.
2. Create a test file (e.g., test.txt) with some content.
3. Run the Script.

Example Output

For a file largefile.zip (1 MB) with chunk size 262144 (256 KB):

Python Output Code

Enter the path to the file you want to split: largefile.zip
Enter the chunk size (in bytes): 262144
Created: largefile_part1 (262144/1048576 bytes processed)
Created: largefile_part2 (524288/1048576 bytes processed)
Created: largefile_part3 (786432/1048576 bytes processed)
Created: largefile_part4 (1048576/1048576 bytes processed)
File splitting completed successfully!