list_files() not showing generated matplotlib plots in Azure Container Apps session pool

[ElieTaillard]

When using SessionsPythonREPLTool with Azure Container Apps dynamic sessions pool, matplotlib plots generated during execution are not accessible via list_files(), despite successful image generation.

Steps to reproduce:

code = """
import matplotlib.pyplot as plt
plt.plot([1, 2, 3], [1, 2, 3])
plt.show()
"""

# Execution shows image creation
result = tool.execute(code)
# Returns: {"result": {"type": "image", "format": "png"}}

# But files aren't listed
files = tool.list_files()  # Returns []

Environment:

• Azure Container Apps dynamic sessions pool
• Python 3.12
• langchain-azure-dynamic-sessions 0.2.0

Expected: Files generated by matplotlib should be visible in session filesystem
Actual: Empty file list while plots are successfully generated

[feijoes]

@ElieTaillard ptl.show() only displays the plot; it doesn't create a file. Try using ptl.savefig('graph.png') to save it as an image

[ElieTaillard]

Indeed, now that you mention it, it makes sense. So, since I'm using a React agent, I updated the prompt to ensure it properly handles saving visualizations:

enhanced_input = f"""IMPORTANT: When creating visualizations or generating files, you MUST follow these rules:
1. NEVER use plt.show() - it will not work
2. For matplotlib plots: 
   - Use plt.savefig('/mnt/data/your_filename.png')
   - Then plt.close()
3. All files MUST be saved in the /mnt/data/ directory
4. After generating files, DO NOT mention saving them. Instead, refer to them as being available or attached.

Your task: {user_input}
"""