import os
import shutil

def backup_folder(source_folder, target_folder):
    # Source folder check
    if not os.path.exists(source_folder):
        raise Exception(f"Source folder {source_folder} does not exist.")

    # Target folder check
    if not os.path.exists(target_folder):
        os.makedirs(target_folder)

    # Traverse all files and subfolders in the source folder
    for root, dirs, files in os.walk(source_folder):
        # Build the relative path for the current directory
        relative_path = os.path.relpath(root, source_folder)
        target_dir = os.path.join(target_folder, relative_path)

        # Create corresponding subfolders in the target folder
        if not os.path.exists(target_dir):
            os.makedirs(target_dir)

        # Copy each file to the target folder
        for file in files:
            source_file = os.path.join(root, file)
            target_file = os.path.join(target_dir, file)
            shutil.copy2(source_file, target_file)

    print("Backup completed successfully.")

# Example usage
# backup_folder("/path/to/source_folder", "/path/to/target_folder")