run-shell-python-file-io

# Run Shell Python File I/O ## When to Use This Skill Use this technique when `execute_code_sandbox` cannot access files in your working directory, but you need to perform file operations (read, write, transform) as part of your task execution. ## The Pattern Instead of using `execute_code_sandbox`, run Python code directly through `run_shell` with explicit path handling. This provides reliable file I/O capabilities within the task workspace. ## How to Apply ### Step 1: Identify File Access Needs Determine which files you need to read from or write to in the working directory. ### Step 2: Write Inline Python via run_shell Construct a Python script that handles your file operations and execute it through `run_shell`: ```bash python3 -c " import os # Get the working directory work_dir = os.getcwd() print(f'Working directory: {work_dir}') # Read a file with open('input.txt', 'r') as f: content = f.read() # Process the content processed = content.upper() # Write to output file with open('output.txt', 'w') as f: f.write(processed) print('File operation complete') " ``` ### Step 3: Handle Complex Logic For more complex operations, write a temporary Python script file first: ```bash cat > /tmp/process.py << 'EOF' import os import json work_dir = os.getcwd() # Read input with open('data.json', 'r') as f: data = json.load(f) # Transform result = {k: v * 2 for k, v in data.items()} # Write output with open('result.json', 'w') as f: json.dump(result, f, indent=2) print(f'Processed {len(data)} items') EOF python3 /tmp/process.py ``` ### Step 4: Verify File Operations After execution, verify the files were created/modified correctly: ```bash ls -la cat output.txt ``` ## Best Practices 1. **Use Absolute or Relative Paths Explicitly**: Always specify file paths clearly; `os.getcwd()` helps confirm your working directory. 2. **Handle Errors Gracefully**: Add try/except blocks to catch file I/O errors: ```python try: with open('file.txt', 'r') as f: content = f.read() except FileNotFoundError: print('File not found') ``` 3. **Use Here-Docs for Complex Scripts**: For scripts longer than a few lines, use bash here-documents to avoid escaping issues. 4. **Clean Up Temporary Files**: If you create temporary scripts, consider removing them after execution. 5. **Check Working Directory First**: Print `os.getcwd()` to confirm you're operating in the expected directory. ## Common Use Cases - Reading configuration files from the workspace - Writing generated reports or outputs - Transforming data files (CSV, JSON, XML) - Batch processing multiple files - Generating structured documents (PDFs, spreadsheets) ## Example: Processing Multiple Files ```bash python3 -c " import os import glob work_dir = os.getcwd() files = glob.glob('*.txt') for f in files: with open(f, 'r') as file: content = file.read() # Process each file with open(f'processed_{f}', 'w') as out: out.write(content.strip().upper()) print(f'Processed {len(files)} files') " ``` ## Troubleshooting | Issue | Solution | |-------|----------| | File not found | Check `os.getcwd()` output; use absolute paths if needed | | Permission denied | Ensure the directory is writable; avoid protected system paths | | Encoding errors | Specify encoding explicitly: `open('file.txt', 'r', encoding='utf-8')` | | Multi-line script issues | Use here-doc (`<< 'EOF'`) instead of `-c` for complex scripts |