I have setup the docker container to run the model evaluation.
I have a list of several thousand file paths in /tmp/files. Write a python script that merges the content int 16 files called /tmp/merged_%d for i in 0..15 where each is approximately the same size. "/tmp/files" is a list of file paths, one per line.
I have a list of several thousand file paths in /tmp/files. Write a python script that merges the content int 16 files called /tmp/merged_%d for i in 0..15 where each is approximately the same size. "/tmp/files" is a list of file paths, one per line.
To solve this problem, we need to merge the contents of several thousand files into 16 output files such that each output file is approximately the same size. The solution involves distributing the files based on their sizes to ensure balanced output files. ### Approach 1. **Read File Paths**: Read the list of file paths from the input file `/tmp/files`. 2. **Collect File Sizes**: For each file path, determine the file size and handle any missing files by skipping them. 3. **Sort Files by Size**: Sort the files in descending order of their sizes. This helps in placing the largest files first, which aids in achieving a balanced distribution. 4. **Distribute Files into Buckets**: Use 16 buckets to distribute the files. For each file, place it in the bucket that currently has the smallest total size. This greedy approach helps in balancing the sizes across all buckets. 5. **Merge Files into Outputs**: For each bucket, write the contents of all its files into the corresponding output file, handling large files by reading and writing in chunks to avoid memory issues. ### Solution Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 | import os def main(): # Read input file paths with open('/tmp/files', 'r') as f: file_paths = [line.strip() for line in f if line.strip()] # Collect file sizes and paths, skipping those that don't exist files = [] for path in file_paths: try: size = os.path.getsize(path) files.append((size, path)) except FileNotFoundError: print(f"Warning: File {path} not found, skipping.") continue # Sort files by size in descending order to optimize distribution files.sort(reverse=True, key=lambda x: x[0]) # Initialize 16 buckets to track total size and associated files buckets = [{'total': 0, 'files': []} for _ in range(16)] # Distribute each file into the bucket with the current smallest total size for size, path in files: min_bucket = min(buckets, key=lambda b: b['total']) min_bucket['files'].append(path) min_bucket['total'] += size # Write each bucket's files into the corresponding merged output file for i, bucket in enumerate(buckets): output_path = f'/tmp/merged_{i}' with open(output_path, 'wb') as outfile: for file_path in bucket['files']: try: with open(file_path, 'rb') as infile: while True: chunk = infile.read(4096) # Read in chunks to handle large files if not chunk: break outfile.write(chunk) except FileNotFoundError: print(f"Warning: File {file_path} not found during merging, skipping.") continue if __name__ == "__main__": main() |
I extracted the following code from that output:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 | import os def main(): # Read input file paths with open('/tmp/files', 'r') as f: file_paths = [line.strip() for line in f if line.strip()] # Collect file sizes and paths, skipping those that don't exist files = [] for path in file_paths: try: size = os.path.getsize(path) files.append((size, path)) except FileNotFoundError: print(f"Warning: File {path} not found, skipping.") continue # Sort files by size in descending order to optimize distribution files.sort(reverse=True, key=lambda x: x[0]) # Initialize 16 buckets to track total size and associated files buckets = [{'total': 0, 'files': []} for _ in range(16)] # Distribute each file into the bucket with the current smallest total size for size, path in files: min_bucket = min(buckets, key=lambda b: b['total']) min_bucket['files'].append(path) min_bucket['total'] += size # Write each bucket's files into the corresponding merged output file for i, bucket in enumerate(buckets): output_path = f'/tmp/merged_{i}' with open(output_path, 'wb') as outfile: for file_path in bucket['files']: try: with open(file_path, 'rb') as infile: while True: chunk = infile.read(4096) # Read in chunks to handle large files if not chunk: break outfile.write(chunk) except FileNotFoundError: print(f"Warning: File {file_path} not found during merging, skipping.") continue if __name__ == "__main__": main() |
Running the following program:
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 | import os def main(): # Read input file paths with open('/tmp/files', 'r') as f: file_paths = [line.strip() for line in f if line.strip()] # Collect file sizes and paths, skipping those that don't exist files = [] for path in file_paths: try: size = os.path.getsize(path) files.append((size, path)) except FileNotFoundError: print(f"Warning: File {path} not found, skipping.") continue # Sort files by size in descending order to optimize distribution files.sort(reverse=True, key=lambda x: x[0]) # Initialize 16 buckets to track total size and associated files buckets = [{'total': 0, 'files': []} for _ in range(16)] # Distribute each file into the bucket with the current smallest total size for size, path in files: min_bucket = min(buckets, key=lambda b: b['total']) min_bucket['files'].append(path) min_bucket['total'] += size # Write each bucket's files into the corresponding merged output file for i, bucket in enumerate(buckets): output_path = f'/tmp/merged_{i}' with open(output_path, 'wb') as outfile: for file_path in bucket['files']: try: with open(file_path, 'rb') as infile: while True: chunk = infile.read(4096) # Read in chunks to handle large files if not chunk: break outfile.write(chunk) except FileNotFoundError: print(f"Warning: File {file_path} not found during merging, skipping.") continue if __name__ == "__main__": main() |
final: True Resulting in output: True