Case 01673

File Converter Skill

A comprehensive file format conversion toolkit supporting documents, images, and spreadsheets.

When to Use

Activate this skill when any of these scenarios occur:

• Document conversion: User wants to convert between PDF and Word formats
• Image conversion: User needs images in a different format (PNG→JPG, JPG→WebP, etc.)
• Spreadsheet conversion: User needs to exchange data between Excel and CSV
• Batch operations: User has multiple files that need converting at once
• Format queries: User asks about supported formats or how to convert specific file types

Supported Conversions

Source Format	Target Format	Script	Notes
.pdf	.docx	scripts/pdf_to_word.py	Extracts text, tables, layout
.docx, .doc	.pdf	scripts/word_to_pdf.py	Requires MS Word on Windows
PNG/JPEG/WebP/BMP/GIF/TIFF	Any other image format	scripts/image_converter.py	Quality control, resize support
.csv	.xlsx	scripts/excel_csv_converter.py	Custom delimiter/encoding
.xlsx, .xls	.csv	scripts/excel_csv_converter.py	Multi-sheet support

Prerequisites

Python Dependencies

Install required packages before first use:

pip install Pillow pdf2docx docx2pdf openpyxl xlrd

Quick install command:

pip install Pillow pdf2docx docx2pdf openpyxl xlrd

Platform-Specific Requirements

• Word → PDF (Windows): Microsoft Word must be installed (docx2pdf uses COM automation)
• PDF → Word: No external software required; uses pdf2docx
• Image conversion: Uses Pillow only, works on all platforms

Workflow Guidelines

Step 1: Identify Conversion Type

Determine what the user wants to convert:

User says "convert this PDF"        → PDF to Word
User says "turn this into PDF"       → Word to PDF  
User says "change this PNG to JPG"   → Image conversion
User says "export this Excel as CSV" → Excel to CSV

Step 2: Check Dependencies

Before running any script, verify required packages are installed:

python -c "import PIL; import pdf2docx; import docx2pdf; import openpyxl"

If imports fail, prompt user to run:

pip install Pillow pdf2docx docx2pdf openpyxl xlrd

Step 3: Execute Appropriate Script

PDF → Word

Single file:

python scripts/pdf_to_word.py <input.pdf> [output.docx]

Batch mode:

python scripts/pdf_to_word.py --batch ./pdf_folder --output-dir ./output_folder

Options:

• --start N: Start from page N (default: 0)
• --end N: End at page N (default: all pages)

Word → PDF

Single file:

python scripts/word_to_pdf.py <input.docx> [output.pdf]

Batch mode:

python scripts/word_to_pdf.py --batch ./docs_folder --output-dir ./pdfs_folder

Check requirements:

python scripts/word_to_pdf.py --check

Image Format Conversion

Single file:

python scripts/image_converter.py <input_image> --format <target_format>

Batch mode:

python scripts/image_converter.py --batch ./images_dir --format webp --output-dir ./webp_dir

Target formats: png, jpg/jpeg, webp, bmp, gif, tiff/tif

Options:

• -q/--quality N: Quality for lossy formats (1-100, default: 95)
• --resize WIDTH HEIGHT: Resize dimensions
• --no-optimize: Disable optimization
• --info: Display image info without converting

Examples:

# High-quality JPEG compression
python scripts/image_converter.py photo.png --format jpg -q 90

# Convert to WebP with smaller size
python scripts/image_converter.py photo.png --format webp -q 80

# Resize while converting
python scripts/image_converter.py large.png --format jpg --resize 1920 1080

# View image info
python scripts/image_converter.py image.png --info

Excel ↔ CSV

CSV → Excel:

python scripts/excel_csv_converter.py data.csv --format xlsx [options]

Excel → CSV:

python scripts/excel_csv_converter.py data.xlsx --format csv [options]

Batch mode:

python scripts/excel_csv_converter.py --batch ./data_dir --format csv

Options:

• -d/--delimiter CHAR: Custom separator (default: comma)
• -e/--encoding ENC: File encoding (default: utf-8)
• --sheet NAME: Specific sheet name (Excel→CSV)
• --sheet-name NAME: Output sheet name (CSV→Excel)
• --no-header: Skip header row
• --info: Show Excel structure info

Examples:

# European-style CSV (semicolon delimited)  
python scripts/excel_csv_converter.py data.csv --format xlsx -d ";"

# Chinese encoding support
python scripts/excel_csv_converter.py data.xlsx --format csv -e gbk

# Export specific sheet
python scripts/excel_csv_converter.py workbook.xlsx --format csv -s "Sales Report"

# View Excel info
python scripts/excel_csv_converter.py data.xlsx --info

Step 4: Verify Results

After each conversion:

1. Confirm output file(s) exist at expected location(s)
2. Report file sizes to user (original vs converted)
3. For batch operations, report success count vs total count
4. If errors occurred, summarize them clearly

Error Handling

Common Issues and Solutions

Error	Cause	Solution
ModuleNotFoundError	Missing package	Run pip install <package>
COMError (Word→PDF)	MS Word not installed	Install MS Office or use alternative
UnicodeDecodeError	Wrong encoding	Specify correct --encoding
FileNotFoundError	Wrong path	Verify input path is absolute or relative correctly
Permission denied	Read-only directory	Use writable output directory

Encoding Guide

When dealing with non-UTF-8 files, common encodings:

• Chinese Windows: gbk / gb18030
• Western Europe: latin-1 / cp1252
• Japanese: shift-jis / cp932
• Auto-detect: Try utf-8 first, then fallback

Best Practices

1. Always use absolute paths when calling scripts to avoid path confusion
2. Create output directories before batch operations if they don't exist
3. Check dependencies once at start of session, not before every call
4. Report results clearly with file paths, sizes, and success/failure counts
5. Handle transparency appropriately — JPEG doesn't support alpha channels
6. Preserve quality defaults are high (95%) but adjust based on use case