Jupyter Lab中Matplotlib InlineBackend报错：NameError: '_fetch_figure_metadata'未定义

This error usually arises from version mismatches between Matplotlib, Jupyter Lab, and its visualization extensions. Try these targeted fixes:

1. Install/verify the Jupyter Lab Matplotlib extension #

Jupyter Lab 4.x depends on the jupyterlab-matplotlib extension to render Matplotlib plots properly. Ensure it's installed:

conda install -c conda-forge jupyterlab-matplotlib

Restart Jupyter Lab completely after installation.

2. Update Matplotlib and ipympl to compatible versions #

Outdated or mismatched versions of Matplotlib and the ipympl backend often trigger this error. Update both packages:

conda update -c conda-forge matplotlib ipympl

3. Switch to the ipympl widget backend #

Replace the inline backend with the widget backend, which integrates better with Jupyter Lab 4.x. Modify your code like this:

import matplotlib.pyplot as plt
%matplotlib widget

img = plt.imread('komodo.jpg')
plt.axis("off")
plt.imshow(img)

This bypasses the faulty metadata fetching logic in the inline backend.

4. Clean Jupyter Lab's cached files #

Corrupted cache from the update might be causing issues. Run this command to clear them:

jupyter lab clean

Restart Jupyter Lab after cleaning.

5. Create a fresh conda environment (last resort) #

If other fixes fail, a fresh environment eliminates leftover package conflicts:

# Create new environment
conda create -n jupyter-lab-fresh python=3.10
# Activate environment
conda activate jupyter-lab-fresh
# Install required packages
conda install -c conda-forge jupyterlab matplotlib ipympl

Launch Jupyter Lab from this environment and test your code again.

内容的提问来源于stack exchange，提问作者Code_Zoro