Python Heredoc Fallback

Python Heredoc Fallback for Code Execution

When to Use

Use this pattern when execute_code_sandbox fails with e2b initialization errors, sandbox connection issues, or other execution environment problems. This is especially reliable for file generation tasks.

Core Pattern

Instead of execute_code_sandbox, run Python code directly in the shell using a heredoc:

python3 << 'EOF'
# Your Python code here
import sys
print("Python code executing in shell")
EOF

Key Syntax Rules

1. Use single-quoted EOF (<< 'EOF') to prevent shell variable expansion within the Python code
2. No indentation before EOF - the closing delimiter must be at the start of the line
3. Install packages first if needed, before the Python heredoc block

Common Use Cases

1. Matplotlib Graph Generation

python3 << 'EOF'
import matplotlib.pyplot as plt
import pandas as pd

# Load data
data = pd.read_excel('input.xlsx')

# Create visualization
plt.figure(figsize=(10, 6))
plt.plot(data['x'], data['y'])
plt.xlabel('X Label')
plt.ylabel('Y Label')
plt.title('Graph Title')
plt.savefig('output_graph.png', dpi=300, bbox_inches='tight')
plt.close()

print("Graph saved successfully")
EOF

2. Python-docx Document Creation

pip install python-docx -q

python3 << 'EOF'
from docx import Document
from docx.shared import Inches, Pt
from docx.enum.text import WD_ALIGN_PARAGRAPH

doc = Document()

# Add title
title = doc.add_heading('Document Title', 0)
title.alignment = WD_ALIGN_PARAGRAPH.CENTER

# Add sections
doc.add_heading('Section 1', level=1)
doc.add_paragraph('Content for section 1.')

# Add table
table = doc.add_table(rows=3, cols=3)
table.style = 'Table Grid'

# Save document
doc.save('output.docx')
print("Document created successfully")
EOF

3. General File Operations

python3 << 'EOF'
import json
import os

# Read input file
with open('input.json', 'r') as f:
    data = json.load(f)

# Process data
result = {'processed': True, 'items': len(data)}

# Write output
with open('output.json', 'w') as f:
    json.dump(result, f, indent=2)

print(f"Processed {result['items']} items")
EOF

Best Practices

1. Install dependencies first: Run pip install package-name -q before the Python block if packages aren't guaranteed to be available
2. Verify file paths: Files are read from and written to the current working directory
3. Add print statements: Include progress/output messages to verify execution succeeded
4. Close resources: Explicitly close matplotlib figures and file handles
5. Handle errors gracefully: Add try/except blocks for production code

Troubleshooting

Advantages Over execute_code_sandbox

• No initialization overhead - runs immediately in existing shell
• Persistent environment - maintains state across multiple commands
• Direct file system access - no sandbox isolation issues
• Full system Python - access to all installed packages
• Reliable for large files - no sandbox size restrictions