pythonimageipythondrawpython-3.12

IPython.display does not show any image at all but <IPython.core.display.Image object>

I am trying to show LangChain graph in my python module code. Not Jupiter notebook. However, the following code snippet:

from IPython.display import Image, display
from langgraph.graph import StateGraph, MessagesState
graph_builder = StateGraph(MessagesState)
simple_graph = graph_builder.compile()
display(Image(simple_graph.get_graph().draw_mermaid_png()))

shows: <IPython.core.display.Image object> instead of the graph. I am on Ubuntu.

Question: Can IPython be used in python module code? According to https://ipython.org/, it seems only possible for the Jupyter Notebook environment. If that's the case, how to use matplotlib or pillow to plot the graph?

Solution

  • Have to save the image to a file and use pillow to show() it:

    from PIL import Image

png_graph = simple_graph.get_graph().draw_mermaid_png()

# Save the PNG data to a file
with open("/tmp/graph.png", "wb") as f:
    f.write(png_graph)
img = Image.open("/tmp/graph.png")
img.show()