pdf-gen-fallback-dee20c

PDF Generation Fallback Workflow

Purpose

When execute_code_sandbox returns opaque or unhelpful errors during document/PDF generation, use run_shell with direct python -c execution as a reliable alternative. This pattern includes library availability checks and explicit error handling.

When to Use

• execute_code_sandbox fails with unclear error messages during document generation
• PDF, report, or document creation tasks are failing unexpectedly
• You need more control over the Python execution environment

Step-by-Step Instructions

1. Check Library Availability

Before attempting generation, verify required libraries are installed:

run_shell: python -c "import reportlab; print('reportlab OK')"
run_shell: python -c "import fpdf; print('fpdf OK')"
run_shell: python -c "import PyPDF2; print('PyPDF2 OK')"

If a library is missing, install it:

run_shell: pip install reportlab --quiet

2. Execute Generation via run_shell

Instead of execute_code_sandbox, use run_shell with python -c:

run_shell: python -c "
from reportlab.lib.pagesizes import letter
from reportlab.pdfgen import canvas
c = canvas.Canvas('output.pdf', pagesize=letter)
c.drawString(100, 750, 'Document Content')
c.save()
print('PDF generated successfully')
"

3. Handle Errors Explicitly

Wrap generation code with try/except and capture stderr:

run_shell: python -c "
import sys
try:
    # Your generation code here
    from reportlab.pdfgen import canvas
    c = canvas.Canvas('output.pdf')
    c.drawString(100, 750, 'Content')
    c.save()
    print('SUCCESS: PDF created')
    sys.exit(0)
except Exception as e:
    print(f'ERROR: {type(e).__name__}: {e}', file=sys.stderr)
    sys.exit(1)
" 2>&1

4. Verify Output File

After generation, confirm the file was created:

run_shell: ls -la output.pdf
run_shell: file output.pdf

5. Fallback Hierarchy

If the first approach fails, try alternatives in this order:

1. reportlab - Full-featured PDF generation
2. fpdf - Simpler PDF library
3. wkhtmltopdf - HTML to PDF conversion
4. Direct text/Markdown output as last resort

Example: Complete Workflow

# Step 1: Check library
run_shell: python -c "import reportlab; print('OK')"

# Step 2: Generate with error handling
run_shell: python -c "
import sys
try:
    from reportlab.lib.pagesizes import letter
    from reportlab.pdfgen import canvas
    c = canvas.Canvas('report.pdf', pagesize=letter)
    c.setTitle('Surveillance Report')
    c.drawString(100, 750, 'Revised Surveillance Report')
    c.drawString(100, 730, 'Summary: Key findings documented')
    c.save()
    print('SUCCESS')
except Exception as e:
    print(f'FAILED: {e}', file=sys.stderr)
    sys.exit(1)
"

# Step 3: Verify
run_shell: test -f report.pdf && echo 'File exists' || echo 'File missing'

Troubleshooting

Issue	Solution
Module not found	pip install <module> --quiet
Permission denied	Check output directory permissions
Font errors	Use default fonts or install font packages
Encoding issues	Specify encoding explicitly in string operations

Best Practices

• Always capture both stdout and stderr for debugging
• Exit with proper status codes (0 for success, 1 for failure)
• Keep generation code concise when using python -c
• For complex generation, write a temporary .py file instead
• Test library availability before attempting generation